Coexistence of different radio access technologies or services on a same carrier

ABSTRACT

A method of a user equipment (UE) operating with a new radio (NR) radio access technology (RAT). The method comprises receiving synchronization signals and a master information block (MIB) in a first bandwidth (BW) and receiving a physical downlink control channel (PDCCH) in a second BW, wherein the second BW is indicated by an offset in the MIB relative to the first BW and the PDCCH conveys a downlink control information (DCI) format that configures a reception of a first system information block (SIB).

CROSS-REFERENCE TO RELATED APPLICATIONS AND CLAIM OF PRIORITY

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 62/383,649, filed on Sep. 6, 2016, entitled “LowLatency Transmissions from a User Equipment,” U.S. Provisional PatentApplication Ser. No. 62/395,709, filed on Sep. 16, 2016, entitled“Coexistence of Different Radio Access Technologies on a Same Carrier,”U.S. Provisional Patent Application Ser. No. 62/402,245, filed on Sep.30, 2016, entitled “Low Latency Transmissions from a User Equipment,”and U.S. Provisional Patent Application Ser. No. 62/413,147, filed onOct. 26, 2016, entitled “Low Latency Transmissions from a UserEquipment.” The content of the above-identified patent document isincorporated herein by reference.

TECHNICAL FIELD

The present application relates generally to a wireless communicationsystem. More specifically, this disclosure relates to coexistence on asame carrier for user equipments (UEs).

BACKGROUND

A user equipment (UE) is commonly referred to as a terminal or a mobilestation, can be fixed or mobile, and can be a cellular phone, a personalcomputer device, or an automated device. A gNB is generally a fixedstation and can also be referred to as a base station, an access point,or other equivalent terminology. A communication system includes adownlink (DL) that refers to transmissions from a base station or one ormore transmission points to UEs and an uplink (UL) that refers totransmissions from UEs to a base station or to one or more receptionpoints.

SUMMARY

The present disclosure relates to a pre-5^(th)-generation (5G) or 5Gcommunication system or new radio (NR) radio access technology (RAT) tobe provided for supporting higher data rates beyond 4^(th)-generation(4G) communication system such as long term evolution (LTE) RAT. Thepresent disclosure relates to supporting LTE and NR coexistence when anLTE scheduler and an NR scheduler cannot support coordinated schedulingfor UEs operating with an LTE RAT and for UEs operating with an NR RAT,respectively, to supporting LTE and NR coexistence when an LTE schedulerand an NR scheduler can support coordinated scheduling for UEs operatingwith an LTE RAT and for UEs operating with an NR RAT, respectively, andto optimizing support for LTE and NR coexistence when UEs capable ofoperating with an NR RAT are also capable for operating with an LTE RAT.The present disclosure also relates to supporting a transmission for afirst service type during a first time slot without interfering with atransmission for a second service type during a second time slot thatincludes the first time slot, to supporting a transmission for a firstservice type during a first time slot without interfering with anothertransmission for the first service type during the first time slot, to agNB reducing a probability of collision between a non-configuredtransmission and a configured transmission and to reduce a probabilityof collision between two non-configured transmissions, to a gNBmultiplexing, over a common set of frequency resources and during a sametime, control transmissions to UEs supporting a first service type usinga first symbol duration for data transmission and to UEs supporting asecond service using a second symbol duration for data transmissions,and to a UE to informing a gNB of a UE identity and of parameters for atransmission that is not configured by the gNB.

In one embodiment, a user equipment (UE) operating with a new radio (NR)radio access technology (RAT) is provided. The UE comprises atransceiver configured to receive synchronization signals and a masterinformation block (MIB) in a first bandwidth (BW) and receive a physicaldownlink control channel (PDCCH) in a second BW wherein the second BW isindicated by an offset in the MIB relative to the first BW and the PDCCHconveys a downlink control information (DCI) format that configures areception of a first system information block (SIB).

In another embodiment, a first base station operating with a new-radio(NR) radio access technology (RAT) is provided. The first base stationcomprises a transceiver configured to transmit, to a second base stationthat uses a long term evolution (LTE) RAT, a first signal over a firstlink, wherein the first signal indicates a bandwidth for transmission ofsynchronization signals and a first system information block accordingto the NR RAT.

In yet another embodiment, a method of a user equipment (UE) operatingwith a new radio (NR) radio access technology (RAT) is provided. Themethod comprises receiving synchronization signals and a masterinformation block (MIB) in a first bandwidth (BW) and receiving aphysical downlink control channel (PDCCH) in a second BW wherein thesecond BW is indicated by an offset in the MIB relative to the first BWand the PDCCH conveys a downlink control information (DCI) format thatconfigures a reception of a first system information block (SIB).

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and derivatives referto any direct or indirect communication between two or more elements,whether or not those elements are in physical contact with one another.The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

Aspects, features, and advantages of the present disclosure are readilyapparent from the following detailed description, simply by illustratinga number of particular embodiments and implementations, including thebest mode contemplated for carrying out the present disclosure. Thepresent disclosure is also capable of other and different embodiments,and its several details can be modified in various obvious respects, allwithout departing from the spirit and scope of the present disclosure.Accordingly, the drawings and description are to be regarded asillustrative in nature, and not as restrictive. The present disclosureis illustrated by way of example, and not by way of limitation, in thefigures of the accompanying drawings.

In the following, both frequency division duplexing (FDD) and timedivision duplexing (TDD) are considered as the duplex method for DL andUL signaling.

Although exemplary descriptions and embodiments to follow assumeorthogonal frequency division multiplexing (OFDM) or orthogonalfrequency division multiple access (OFDMA), this present disclosure canbe extended to other OFDM-based transmission waveforms or multipleaccess schemes such as filtered OFDM (F-OFDM) or OFDM with zero cyclicprefix.

This present disclosure covers several components which can be used inconjunction or in combination with one another, or can operate asstandalone schemes

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure;

FIG. 2 illustrates an example gNB according to embodiments of thepresent disclosure;

FIG. 3 illustrates an example UE according to embodiments of the presentdisclosure;

FIG. 4A illustrates a high-level diagram of an orthogonal frequencydivision multiple access transmit path according to embodiments of thepresent disclosure;

FIG. 4B illustrates a high-level diagram of an orthogonal frequencydivision multiple access receive path according to embodiments of thepresent disclosure;

FIG. 5 illustrates an example slot structure for DL transmissionsaccording to embodiments of the present disclosure;

FIG. 6 illustrates an example slot structure for PUSCH transmissionaccording to embodiments of the present disclosure;

FIG. 7 illustrates an example transmitter structure using OFDM accordingto embodiments of the present disclosure;

FIG. 8 illustrates an example receiver structure using OFDM according toembodiments of the present disclosure;

FIG. 9 illustrates an example URLLC transmission from a UE to a gNBaccording to embodiments of the present disclosure;

FIG. 10 illustrates an example adaptation of an LTE DL cell BW andassociated signaling to LTE UEs and NR UEs according to embodiments ofthe present disclosure;

FIG. 11 illustrates an example use of LTE MBSFN SFs as NR slotsaccording to embodiments of the present disclosure;

FIG. 12 illustrates an example process for an NR UE to synchronize andobtain SI on a cell supporting LTE and NR coexistence according toembodiments of the present disclosure;

FIG. 13 illustrates an example structure for LTE and NR coexistence in aDL cell BW according to embodiments of the present disclosure;

FIG. 14 illustrates an example hybrid operation for an NR UE using anLTE DL cell BW and an NR DL cell BW according to embodiments of thepresent disclosure;

FIG. 15 illustrates an example process for an NR UE to determine whetherto receive a PDSCH using a first transmission structure based on an LTERAT or using a second transmission structure based on an NR RATaccording to embodiments of the present disclosure;

FIG. 16 illustrates an example process for a UE supporting a firstservice type to determine a transmission BW according to embodiments ofthe present disclosure;

FIG. 17 illustrates an example process for a UE to determine atransmission power according to embodiments of the present disclosure;

FIG. 18 illustrates an example dependence of symbol duration for controlsignaling on supported service types according to embodiments of thepresent disclosure;

FIG. 19 illustrates an example process for a gNB to communicate at thebeginning of a second time slot a total BW available for potentialtransmissions from UEs during a first time slot according to embodimentsof the present disclosure;

FIG. 20 illustrates an example process for a UE to determine a CP to usefor transmissions according to embodiments of the present disclosure;

FIG. 21 illustrates an example arrangement of RS, control symbols, anddata symbols in a time slot used by a UE to transmit a non-configuredtransmission according to embodiments of the present disclosure; and

FIG. 22 illustrates an example process for a UE to determine a number ofRBs and a transmission power for a non-configured transmission accordingto embodiments of the present disclosure.

DETAILED DESCRIPTION

FIG. 1 through FIG. 22, discussed below, and the various embodimentsused to describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artmay understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device.

The following documents and standards descriptions are herebyincorporated by reference into the present disclosure as if fully setforth herein: 3GPP TS 36.211 v13.2.0, “E-UTRA, Physical channels andmodulation” (REF1); 3GPP TS 36.212 v13.2.0, “E-UTRA, Multiplexing andChannel coding” (REF2); 3GPP TS 36.213 v13.2.0, “E-UTRA, Physical LayerProcedures” (REF3); 3GPP TS 36.321 v13.2.0, “E-UTRA, Medium AccessControl (MAC) protocol specification;” (REF4) and 3GPP TS 36.331v13.2.0, “E-UTRA, Radio Resource Control (RRC) Protocol Specification”(REF5).

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a “beyond 4G network” or a“post LTE system.”

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission coverage, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques and the like arediscussed in 5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud radioaccess networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul communication, moving network,cooperative communication, coordinated multi-points (CoMP) transmissionand reception, interference mitigation and cancellation and the like.

In the 5G system, hybrid frequency shift keying and quadrature amplitudemodulation (FQAM) and sliding window superposition coding (SWSC) as anadaptive modulation and coding (AMC) technique, and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse codemultiple access (SCMA) as an advanced access technology have beendeveloped.

FIGS. 1-4B below describe various embodiments implemented in wirelesscommunications systems and with the use of OFDM or OFDMA communicationtechniques. The descriptions of FIGS. 1-3 are not meant to implyphysical or architectural limitations to the manner in which differentembodiments may be implemented. Different embodiments of the presentdisclosure may be implemented in any suitably-arranged communicationssystem.

FIG. 1 illustrates an example wireless network 100 according toembodiments of the present disclosure. The embodiment of the wirelessnetwork 100 shown in FIG. 1 is for illustration only. Other embodimentsof the wireless network 100 could be used without departing from thescope of this disclosure.

As shown in FIG. 1, the wireless network 100 includes a gNB 101, a gNB102, and a gNB 103. The gNB 101 communicates with the gNB 102 and thegNB 103. The gNB 101 also communicates with at least one network 130,such as the Internet, a proprietary internet protocol (IP) network, orother data network.

The gNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe gNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business (SB); a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 116, which may be amobile device (M), such as a cell phone, a wireless laptop, a wirelessPDA, or the like. The gNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe gNB 103. The second plurality of UEs includes the UE 115 and the UE116. In some embodiments, one or more of the gNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, LTE,LTE-A, WiMAX, WiFi, or other wireless communication techniques.

Depending on the network type, the term “base station” or “BS” can referto any component (or collection of components) configured to providewireless access to a network, such as transmit point (TP),transmit-receive point (TRP), an enhanced base station (eNodeB or gNB),gNB, a macrocell, a femtocell, a WiFi access point (AP), or otherwirelessly enabled devices. Base stations may provide wireless access inaccordance with one or more wireless communication protocols, e.g., 5G3GPP new radio interface/access (NR), long term evolution (LTE), LTEadvanced (LTE-A), high speed packet access (HSPA), Wi-Fi802.11a/b/g/n/ac, etc.

For ease of reference, a base station providing service for a first RATsuch as 5 G/NR is referred to as gNB while a base station providingservice for a second RAT such as LTE is referred to as eNB. It ispossible that an eNB and a gNB correspond to a same base station. Theterms “base station” and “TRP” can be used interchangeably in thisdisclosure to refer to network infrastructure components that providewireless access to remote terminals. Also, depending on the networktype, the term UE can refer to any component such as a mobile station, asubscriber station, a remote terminal, a wireless terminal, a receivepoint, or a user device. A UE can be a mobile device or a stationarydevice.

For the sake of convenience, the terms “eNodeB” and “gNB” are used inthis patent document to refer to network infrastructure components thatprovide wireless access to remote terminals. Also, depending on thenetwork type, other well-known terms may be used instead of “userequipment” or “UE,” such as “mobile station,” “subscriber station,”“remote terminal,” “wireless terminal,” or “user device.” For the sakeof convenience, the terms “user equipment” and “UE” are used in thispatent document to refer to remote wireless equipment that wirelesslyaccesses a gNB, whether the UE is a mobile device (such as a mobiletelephone or smartphone) or is normally considered a stationary device(such as a desktop computer or vending machine).

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with gNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the gNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, one or more of the UEs 111-116include circuitry, programming, or a combination thereof, for efficientchannel state information (CSI) reporting on an uplink channel in anadvanced wireless communication system. In certain embodiments, and oneor more of the gNBs 101-103 includes circuitry, programming, or acombination thereof.

Although FIG. 1 illustrates one example of a wireless network 100,various changes may be made to FIG. 1. For example, the wireless network100 could include any number of gNBs and any number of UEs in anysuitable arrangement. Also, the gNB 101 could communicate directly withany number of UEs and provide those UEs with wireless broadband accessto the network 130. Similarly, each gNB 102-103 could communicatedirectly with the network 130 and provide UEs with direct wirelessbroadband access to the network 130. Further, the gNBs 101, 102, and/or103 could provide access to other or additional external networks, suchas external telephone networks or other types of data networks.

FIG. 2 illustrates an example gNB 102 according to embodiments of thepresent disclosure. The embodiment of the gNB 102 illustrated in FIG. 2is for illustration only, and the gNBs 101 and 103 of FIG. 1 could havethe same or similar configuration. However, gNBs come in a wide varietyof configurations, and FIG. 2 does not limit the scope of thisdisclosure to any particular implementation of a gNB.

As shown in FIG. 2, the gNB 102 includes multiple antennas 205 a-205 n,multiple radio frequency (RF) transceivers 210 a-210 n, transmit (TX)processing circuitry 215, and receive (RX) processing circuitry 220. ThegNB 102 also includes a controller/processor 225, a memory 230, and abackhaul or network interface 235.

The RF transceivers 210 a-210 n receive, from the antennas 205 a-205 n,incoming RF signals, such as signals transmitted by UEs in the network100. The RF transceivers 210 a-210 n down-convert the incoming RFsignals to generate intermediate frequency (IF) or baseband signals. TheIF or baseband signals are sent to the RX processing circuitry 220,which generates processed baseband signals by filtering, decoding,and/or digitizing the baseband or IF signals. The RX processingcircuitry 220 transmits the processed baseband signals to thecontroller/processor 225 for further processing.

In some embodiments, the RF transceivers 210 a-210 n are capable oftransmitting, to another eNB (e.g., base station) a signal indicatingbandwidth information for synchronization signal and system informationblock, and receiving, from the other eNB, a signal indicating a numberof decoding operation for PDCCH to configure a UE. In some embodiments,the RF transceivers 210 a-210 n are capable of receiving, from anotherbase station, a signal including configuration information for apredetermined number of subframes in normal and MBSFN subframes based onLTE RAT, and information for a number of subframe symbols in normal andMBSFN subframes. In some embodiments, the RF transceivers 210 a-210 nare capable of receiving a signal indicating a cell identity and anumber of antennal ports for CRS, and receiving a signal comprisingconfiguration information for SRS, downlink, uplink, and specialsubframes according to the LTE RAT.

The TX processing circuitry 215 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 225. The TX processing circuitry 215 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 210 a-210 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 215 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 205 a-205 n.

The controller/processor 225 can include one or more processors or otherprocessing devices that control the overall operation of the gNB 102.For example, the controller/processor 225 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 210 a-210 n, the RX processing circuitry 220, andthe TX processing circuitry 215 in accordance with well-knownprinciples. The controller/processor 225 could support additionalfunctions as well, such as more advanced wireless communicationfunctions. For instance, the controller/processor 225 could support beamforming or directional routing operations in which outgoing signals frommultiple antennas 205 a-205 n are weighted differently to effectivelysteer the outgoing signals in a desired direction. Any of a wide varietyof other functions could be supported in the gNB 102 by thecontroller/processor 225.

In some embodiments, the controller/processor 225 includes at least onemicroprocessor or microcontroller. As described in more detail below,the gNB 102 may include circuitry, programming, or a combination thereoffor processing of an uplink channel and/or a downlink channel. Forexample, controller/processor 225 can be configured to execute one ormore instructions, stored in memory 230, that are configured to causethe controller/processor to process the signal.

The controller/processor 225 is also capable of executing programs andother processes resident in the memory 230, such as an operating system(OS). The controller/processor 225 can move data into or out of thememory 230 as required by an executing process.

The controller/processor 225 is also coupled to the backhaul or networkinterface 235. The backhaul or network interface 235 allows the gNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 235 could support communications overany suitable wired or wireless connection(s). For example, when the gNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 235 could allow the gNB102 to communicate with other gNBs over a wired or wireless backhaulconnection. When the gNB 102 is implemented as an access point, theinterface 235 could allow the gNB 102 to communicate over a wired orwireless local area network or over a wired or wireless connection to alarger network (such as the Internet). The interface 235 includes anysuitable structure supporting communications over a wired or wirelessconnection, such as an Ethernet or RF transceiver.

The memory 230 is coupled to the controller/processor 225. Part of thememory 230 could include a RAM, and another part of the memory 230 couldinclude a Flash memory or other ROM.

Although FIG. 2 illustrates one example of gNB 102, various changes maybe made to FIG. 2. For example, the gNB 102 could include any number ofeach component shown in FIG. 2. As a particular example, an access pointcould include a number of interfaces 235, and the controller/processor225 could support routing functions to route data between differentnetwork addresses. As another particular example, while shown asincluding a single instance of TX processing circuitry 215 and a singleinstance of RX processing circuitry 220, the gNB 102 could includemultiple instances of each (such as one per RF transceiver). Also,various components in FIG. 2 could be combined, further subdivided, oromitted and additional components could be added according to particularneeds.

FIG. 3 illustrates an example UE 116 according to embodiments of thepresent disclosure. The embodiment of the UE 116 illustrated in FIG. 3is for illustration only, and the UEs 111-115 of FIG. 1 could have thesame or similar configuration. However, UEs come in a wide variety ofconfigurations, and FIG. 3 does not limit the scope of this disclosureto any particular implementation of a UE.

As shown in FIG. 3, the UE 116 includes an antenna 305, an RFtransceiver 310, TX processing circuitry 315, a microphone 320, and RXprocessing circuitry 325. The UE 116 also includes a speaker 330, aprocessor 340, an input/output (I/O) interface (IF) 345, a touchscreen350, a display 355, and a memory 360. The memory 360 includes an OS 361and one or more applications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RFsignal transmitted by a gNB of the network 100. The RF transceiver 310down-converts the incoming RF signal to generate an IF or basebandsignal. The IF or baseband signal is sent to the RX processing circuitry325, which generates a processed baseband signal by filtering, decoding,and/or digitizing the baseband or IF signal. The RX processing circuitry325 transmits the processed baseband signal to the speaker 330 (such asfor voice data) or to the processor 340 for further processing (such asfor web browsing data).

In some embodiments, the RF transceiver 310 is capable of receivingsynchronization signals, an MIB, and PDCCH. In such embodiments, SIBindicates a number of antenna ports used for CRS according to an LTERAT. In some embodiments, the RF transceiver 310 is capable oftransmitting a signal according to the NR RAT with a power determinedaccording to a path-loss measured from the CRS and receiving anindication to perform decoding operations for PDCCH. In someembodiments, the RF transceiver 310 is capable of receivingsynchronization signals according to an LTE RAT, a subframe number, anda downlink BW for an LTE RAT. In some embodiments, the RF transceiver310 is capable of excluding from NR RAT receptions symbols, subcarriersof the CSI-RS, and a number of subframe symbols.

The TX processing circuitry 315 receives analog or digital voice datafrom the microphone 320 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the processor 340.The TX processing circuitry 315 encodes, multiplexes, and/or digitizesthe outgoing baseband data to generate a processed baseband or IFsignal. The RF transceiver 310 receives the outgoing processed basebandor IF signal from the TX processing circuitry 315 and up-converts thebaseband or IF signal to an RF signal that is transmitted via theantenna 305.

The processor 340 can include one or more processors or other processingdevices and execute the OS 361 stored in the memory 360 in order tocontrol the overall operation of the UE 116. For example, the processor340 could control the reception of forward channel signals and thetransmission of reverse channel signals by the RF transceiver 310, theRX processing circuitry 325, and the TX processing circuitry 315 inaccordance with well-known principles. In some embodiments, theprocessor 340 includes at least one microprocessor or microcontroller.

The processor 340 is also capable of executing other processes andprograms resident in the memory 360, such as processes for referencesignal on a downlink channel. The processor 340 can move data into orout of the memory 360 as required by an executing process. In someembodiments, the processor 340 is configured to execute the applications362 based on the OS 361 or in response to signals received from gNBs oran operator. The processor 340 is also coupled to the I/O interface 345,which provides the UE 116 with the ability to connect to other devices,such as laptop computers and handheld computers. The I/O interface 345is the communication path between these accessories and the processor340.

The processor 340 is also coupled to the touchscreen 350 and the display355. The operator of the UE 116 can use the touchscreen 350 to enterdata into the UE 116. The display 355 may be a liquid crystal display,light emitting diode display, or other display capable of rendering textand/or at least limited graphics, such as from web sites.

In some embodiments, the processor 340 is capable of determining symbolsand subcarriers for synchronization signals and of an MIB according tothe LTE RAT and performing a rate matching operation for NR RATreceptions around the symbols and subcarriers. In such embodiments, anSIB indicates configuration information for CSI-RS, a partitioning of apredetermined number of subframes in a normal and MBSFN subframesaccording to the LTE, and a number of subframe symbols in normal andMBSFN subframe.

The memory 360 is coupled to the processor 340. Part of the memory 360could include an RAM, and another part of the memory 360 could include aFlash memory or other ROM.

Although FIG. 3 illustrates one example of UE 116, various changes maybe made to FIG. 3. For example, various components in FIG. 3 could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, theprocessor 340 could be divided into multiple processors, such as one ormore central processing units (CPUs) and one or more graphics processingunits (GPUs). Also, while FIG. 3 illustrates the UE 116 configured as amobile telephone or smartphone, UEs could be configured to operate asother types of mobile or stationary devices.

FIG. 4A is a high-level diagram of transmit path circuitry 400. Forexample, the transmit path circuitry 400 may be used for an OFDMAcommunication. FIG. 4B is a high-level diagram of receive path circuitry450. For example, the receive path circuitry 450 may be used for anOFDMA communication. In FIGS. 4A and 4B, for downlink communication, thetransmit path circuitry 400 may be implemented in a base station (e.g.,gNB) 102 or a relay station, and the receive path circuitry 450 may beimplemented in a user equipment (e.g. user equipment 116 of FIG. 1). Inother examples, for uplink communication, the receive path circuitry 450may be implemented in a base station (e.g. gNB 102 of FIG. 1) or a relaystation, and the transmit path circuitry 400 may be implemented in auser equipment (e.g. user equipment 116 of FIG. 1).

Transmit path circuitry 400 comprises channel coding and modulationblock 405, serial-to-parallel (S-to-P) block 410, size N inverse fastFourier transform (IFFT) block 415, parallel-to-serial (P-to-S) block420, add cyclic prefix block 425, and up-converter (UC) 430. Receivepath circuitry 450 comprises down-converter (DC) 455, remove cyclicprefix block 460, serial-to-parallel (S-to-P) block 465, Size n FFTblock 470, parallel-to-serial (P-to-S) block 475, and channel decodingand demodulation block 480.

At least some of the components in FIGS. 4A and 4B may be implemented insoftware, while other components may be implemented by configurablehardware or a mixture of software and configurable hardware. Inparticular, it is noted that the FFT blocks and the IFFT blocksdescribed in this disclosure document may be implemented as configurablesoftware algorithms, where the value of size N may be modified accordingto the implementation.

Furthermore, although this disclosure is directed to an embodiment thatimplements the fast Fourier transform and the inverse fast Fouriertransform, this is by way of illustration only and should not beconstrued to limit the scope of the disclosure. It may be appreciatedthat in an alternate embodiment of the disclosure, the Fast FourierTransform functions and the Inverse Fast Fourier Transform functions mayeasily be replaced by discrete Fourier transform (DFT) functions andinverse discrete Fourier transform (IDFT) functions, respectively. Itmay be appreciated that for DFT and IDFT functions, the value of the Nvariable may be any integer number (i.e., 1, 4, 3, 4, etc.), while forFFT and IFFT functions, the value of the N variable may be any integernumber that is a power of two (i.e., 1, 2, 4, 8, 16, etc.).

In transmit path circuitry 400, channel coding and modulation block 405receives a set of information bits, applies coding (e.g., LDPC coding)and modulates (e.g., quadrature phase shift keying (QPSK) or quadratureamplitude modulation (QAM)) the input bits to produce a sequence offrequency-domain modulation symbols. Serial-to-parallel block 410converts (i.e., de-multiplexes) the serial modulated symbols to paralleldata to produce N parallel symbol streams where N is the IFFT/FFT sizeused in BS 102 and UE 116. Size N IFFT block 415 then performs an IFFToperation on the N parallel symbol streams to produce time-domain outputsignals. Parallel-to-serial block 420 converts (i.e., multiplexes) theparallel time-domain output symbols from Size N IFFT block 415 toproduce a serial time-domain signal. Add cyclic prefix block 425 theninserts a cyclic prefix to the time-domain signal. Finally, up-converter430 modulates (i.e., up-converts) the output of add cyclic prefix block425 to RF frequency for transmission via a wireless channel. The signalmay also be filtered at baseband before conversion to RF frequency.

The transmitted RF signal arrives at UE 116 after passing through thewireless channel, and reverse operations to those at gNB 102 areperformed. Down-converter 455 down-converts the received signal tobaseband frequency, and remove cyclic prefix block 460 removes thecyclic prefix to produce the serial time-domain baseband signal.Serial-to-parallel block 465 converts the time-domain baseband signal toparallel time-domain signals. Size N FFT block 470 then performs an FFTalgorithm to produce N parallel frequency-domain signals.Parallel-to-serial block 475 converts the parallel frequency-domainsignals to a sequence of modulated data symbols. Channel decoding anddemodulation block 480 demodulates and then decodes the modulatedsymbols to recover the original input data stream.

Each of gNBs 101-103 may implement a transmit path that is analogous totransmitting in the downlink to user equipment 111-116 and may implementa receive path that is analogous to receiving in the uplink from userequipment 111-116. Similarly, each one of user equipment 111-116 mayimplement a transmit path corresponding to the architecture fortransmitting in the uplink to gNBs 101-103 and may implement a receivepath corresponding to the architecture for receiving in the downlinkfrom gNBs 101-103.

DL transmissions or UL transmissions can be based on an OFDM waveformincluding a variant using DFT precoding that is known as DFT-spread-OFDMthat is typically applicable to UL transmissions.

In the following, subframe (SF) refers to a transmission time unit forthe LTE RAT and slot refers to a transmission time unit for an NR RAT.For example, the slot duration can be a sub-multiple of the SF duration.NR can use a different DL or UL slot structure than an LTE SF structure.Differences can include a structure for transmitting PDCCH, locationsand structure of DMRS, transmission duration, and so on. Further, eNBrefers to a base station serving UEs operating with LTE RAT and gNBrefers to a base station serving UEs operating with NR RAT. For brevity,the term slot is subsequently used but corresponding descriptions forthe DL or UL transmission and reception structures are also applicablefor a SF.

An SF (or a slot) is part of frame that includes ten SFs (or slots). Aframe can be identified by a system frame number (SFN) ranging from 0 to1023 (and can be represented by 10 binary elements). For brevity,remaining descriptions assume that an OFDM symbol has a normal cyclicprefix (CP) but the embodiments are also directly applicable to the casethat an OFDM symbol has an extended CP. Some SFs (or slots) in a framecan be configured as multicast-broadcast SFN (MBSFN) SFs (or slots) oras almost-blank (ABS) SFs (or slots).

A slot includes one or more slot symbols. A BW unit is referred to as aresource block (RB). One RB includes a number of sub-carriers (SCs). Forexample, a slot can have duration of half millisecond or of onemillisecond, include 7 symbols or 14 symbols, respectively, and a RB canhave a BW of 180 KHz and include 12 SCs with inter-SC spacing of 15 KHzor 60 KHz. A BW reception capability or a BW transmission for a UE canbe smaller than a DL system BW or an UL system BW, respectively, anddifferent UEs can be configured DL receptions or UL transmissions indifferent parts of a DL system BW or of an UL system BW, respectively,per slot.

DL signals include data signals conveying information content, controlsignals conveying DL control information (DCI), and reference signals(RS) that are also known as pilot signals. A gNB transmits datainformation or DCI through respective physical DL shared channels(PDSCHs) or physical DL control channels (PDCCHs). A gNB transmits oneor more of multiple types of RS including common RS (CRS), channel stateinformation RS (CSI-RS) and demodulation RS (DMRS). A CRS can betransmitted over an entire DL cell BW in subcarriers determined by aphysical cell identity and can be used by UEs to demodulate data orcontrol signals, for time tracking or frequency tracking, or to performmeasurements such as a RS received power (RSRP) measurement to determinea path-loss (PL). To reduce CRS overhead, an eNB can transmit a CSI-RSwith a smaller density in the time or frequency domain than a CRS. ACSI-RS is intended for UEs to measure CSI or perform PL measurements. ADMRS is typically transmitted only in the BW of a respective PDCCH orPDSCH and a UE can use the DMRS to demodulate DCI or data information. ADL DMRS or CSI-RS can be constructed by a Constant amplitude zeroautocorrelation (CAZAC) sequence or a pseudo-noise (PN) sequence.

For channel measurement, non-zero power CSI-RS (NZP CSI-RS) resourcesare used. For interference measurement reports (IMRs), CSI interferencemeasurement (CSI-IM) resources associated with a zero power CSI-RS (ZPCSI-RS) configuration are used. A CSI process includes NZP CSI-RS andCSI-IM resources. A UE can determine CSI-RS transmission parametersthrough higher layer signaling, such as RRC signaling from a gNB.Transmission instances and resources of a CSI-RS can be indicated by DLcontrol signaling or configured by higher layer signaling. A DMRS istransmitted only in the BW of a respective PDCCH or PDSCH and a UE canuse the DMRS to demodulate data or control information.

DCI can serve several purposes. A DCI format includes informationelements (IEs) and is typically used for scheduling a PDSCH (DL DCIformat) or a PUSCH (UL DCI format) transmission. A DCI format includescyclic redundancy check (CRC) bits in order for a UE to confirm acorrect detection. A DCI format type is identified by a radio networktemporary identifier (RNTI) that scrambles the CRC bits. For a DCIformat scheduling a PDSCH or a PUSCH for a single UE with RRC connectionto an eNB, the RNTI is a cell RNTI (C-RNTI). Different DCI formats maybe associated with different PDSCH or PUSCH Transmission Modes (TMs)configured to a UE. For a DCI format scheduling a PDSCH conveying systeminformation (SI) to a group of UEs, the RNTI is a SI-RNTI.

For a DCI format scheduling a PDSCH providing a response to a randomaccess (RA) from a group of UEs, the RNTI is a RA-RNTI. For a DCI formatscheduling a PDSCH providing contention resolution in Msg4 of a RAprocess, the RNTI is a temporary C-RNTI (TC-RNTI). For a DCI formatscheduling a PDSCH paging a group of UEs, the RNTI is a P-RNTI. For aDCI format providing transmission power control (TPC) commands to agroup of UEs, the RNTI is a TPC-RNTI. Each RNTI type is configured to aUE through higher layer signaling (and the C-RNTI is unique for eachUE). A UE typically decodes at multiple candidate locations forpotential PDCCH transmissions. Additionally, semi-persistent scheduling(SPS) can be used to schedule PDSCH transmissions to or PUSCHtransmissions from a UE without an eNB having to transmit a DCI formatto schedule each such transmission. With SPS, a UE is configured by aneNB through higher layer signaling frequency resources and aperiodically to receive a PDSCH or transmit a PUSCH.

DL signaling also includes transmission of a logical channel thatcarries system control information is referred to as broadcast controlchannel (BCCH). A BCCH is mapped to either a transport channel referredto as a broadcast channel (BCH) or to a DL shared channel (DL-SCH). ABCH is mapped to a physical channel referred to as Physical BCH (PBCH).A DL-SCH is mapped to PDSCH. A master information block (MIB) istransmitted using BCH, while other SI is provided by system informationblocks (SIBs) using DL-SCH (MIB and SIBs constitute the SI). After a UEacquires a physical cell identity (PCID) for a cell, the UE can performDL channel measurement using a CRS to decode PBCH and PDSCH. A MIBincludes a minimal amount of system information that is needed for a UEto be able to receive remaining system information provided by DL-SCH.

A MIB has predefined format and includes information of DL BW, PHICHrelated information, SFN, and spare bits. A UE needs to know a PHICHconfiguration to be able to receive PDCCH which, in turn, is needed toreceive DL-SCH. A PBCH is transmitted using a minimum BW of 6 RBs in thecentral part of a DL cell BW and in SF#0 of four successive frames. MostSI is included in several SIBs. SIB1 mainly includes information relatedto whether a UE is allowed to camp on a respective cell. In case of TDD,SIB1 also includes information about an allocation of UL/DL SFs (UL/DLconfiguration) and configuration of a special SF. SIB1 also includesinformation about a time-domain scheduling of remaining SIBs (SIB2 andbeyond). SIB2 includes information that UEs need in order to be able toaccess a cell. This includes information about an UL cell BW,random-access parameters, and parameters related to UL power control.SIB3-SIB13 mainly includes information related to cell reselection,neighboring-cell-related information, public warning messages, and soon.

FIG. 5 illustrates an example slot or SF structure 500 for DLtransmissions according to embodiments of the present disclosure. Anembodiment of the slot structure 500 shown in FIG. 5 is for illustrationonly. Other embodiments may be used without departing from the scope ofthe present disclosure.

A slot 510 includes N_(symb) ^(DL) symbols 520 where a gNB can transmitdata information, DCI, or DMRS. A DL system BW includes N_(RB) ^(DL)RBs. Each RB includes N_(sc) ^(RB) SCs. A UE is assigned M_(PDSCH) RBsfor a total of M_(sc) ^(PDSCH)=M_(PDSCH)·N_(sc) ^(RB) SCs 530 for aPDSCH transmission BW. A PDCCH conveying DCI is transmitted over controlchannel elements (CCEs) that are substantially spread across a part orall of the DL system BW. A first symbol 540 can be used by the gNB totransmit PDCCH and DMRS associated with PDCCH demodulation. A secondsymbol 550 can be used by the gNB to transmit PDCCH or PDSCH. Remainingsymbols 560 can be used by the gNB to transmit PDSCH, DMRS associatedwith each PDSCH, and CSI-RS. In some slots, the gNB can also transmitsynchronization signals and system information.

In some wireless networks, UL signals include data signals conveyinginformation content, control signals conveying UL control information(UCI), and RS. A UE transmits data information or UCI through arespective physical UL shared channel (PUSCH) or a physical UL controlchannel (PUCCH). When a UE simultaneously transmits data information andUCI, the UE can multiplex both in a PUSCH or the UE can transmit dataand some UCI in a PUSCH and transmit remaining UCI in a PUCCH when aneNB configures the UE for simultaneous PUSCH and PUCCH transmission. UCIincludes HARQ-ACK information, indicating correct or incorrect detectionof data transport blocks (TBs) in a PDSCH, scheduling request (SR)indicating whether a UE has data in the UE's buffer, and CSI enabling aneNB to select appropriate parameters for link adaptation of PDSCH orPDCCH transmissions to a UE. CSI includes a channel quality indicator, aprecoding matrix indicator, and a rank indicator. UL RS includes DMRSand sounding RS (SRS) and can use sequences, such as CAZAC sequences,for the UL RS's transmission.

A UE transmits DMRS only in a BW of a respective PUSCH or PUCCH and aneNB can use a DMRS to demodulate information in a PUSCH or PUCCH. A UEtransmits SRS to provide an eNB with an UL CSI. A SRS transmission froma UE can be periodic (P-SRS, or trigger type 0 SRS) or aperiodic (A-SRS,or trigger type 1 SRS) as triggered by a SRS request field included in aDCI format conveyed by a PDCCH scheduling PUSCH or PDSCH.

One of the fundamental requirements in an operation of a communicationsystem is a capability for a UE to request a connection setup; suchrequest is commonly referred to as random access. Random access is usedfor several purposes, including: initial access when establishing aradio link; re-establishing a radio link after radio-link failure,handover when uplink synchronization needs to be established to a newcell, UL synchronization, UE positioning based on UL measurements, andas an SR if no dedicated SR resources have been configured on a PUCCH.Acquisition of UL timing at a serving eNB is one of the main objectivesof random access; when establishing an initial radio link, arandom-access process also serves for assigning a unique identitythrough a C-RNTI to a UE.

A CSI report from a UE can include a channel quality indicator (CQI)informing a gNB of a largest modulation and coding scheme (MCS) for theUE to detect a data TB with a predetermined block error rate (BLER),such as a 10% BLER, of a precoding matrix indicator (PMI) informing agNB how to combine signals from multiple transmitter antennas inaccordance with a MIMO transmission principle, and of a rank indicator(RI) indicating a transmission rank for a PDSCH. UL RS includes DMRS andSRS. DMRS is transmitted only in a BW of a respective PUSCH or PUCCHtransmission. A gNB can use a DMRS to demodulate information in arespective PUSCH or PUCCH. SRS is transmitted by a UE to provide a gNBwith an UL CSI and, for a TDD system, a SRS transmission can alsoprovide a PMI for DL transmission. Additionally, in order to establishsynchronization or an initial RRC connection with a gNB, a UE cantransmit a physical random access channel.

A PUSCH transmission power from a UE is set with an objective to achievea reliability target for associated data by achieving a respectivetarget received SINR at a serving cell of a gNB while controllinginterference to neighboring cells. UL power control (PC) includesopen-loop PC (OLPC) with cell-specific and UE-specific parameters andclosed-loop PC (CLPC) corrections provided to a UE by a gNB through TPCcommands. When a PUSCH transmission is scheduled by a PDCCH, a TPCcommand is included in a respective DCI format.

A UE can derive a PUSCH transmission power P_(PUSCH,c)(i), in decibelsper milliwatt (dBm), in cell c and slot i as in Equation 1 given by:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min {\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{{10\; {\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)}}\end{matrix}\end{Bmatrix}\lbrack{dBm}\rbrack}}} & {{Equation}\mspace{14mu} (1)}\end{matrix}$

where, P_(CMAX,c)(i) is a maximum UE transmission power in cell c andslot i, M_(PUSCH,c)(i) is a PUSCH transmission BW in RBs in cell c andslot i, P_(O) _(_) _(PUSCH,c)(j) controls a mean received SINR at thegNB in cell c, PL_(c) is a PL estimate computed by the UE for cell c,for j=0 or j=1, α_(c)(j)ε{0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1} isconfigured to the UE by the gNB through higher layer signaling andfractional UL PC is obtained for α_(c)(j)<1 as a PL is not fullycompensated, Δ_(TF,c)(i) is either equal to 0 or is determined by aspectral efficiency of a PUSCH transmission as Δ_(TF,c)(i)=10log₁₀((2^(BPRE·K) ^(s) −1)·β_(offset) ^(PUSCH)) where, K_(S) isconfigured to a UE by higher layer signaling, BPRE=O_(CQI)/N_(RE) forA-CSI sent via PUSCH without UL-SCH data and

$\sum\limits_{r = 0}^{C - 1}{K_{r}/N_{RE}}$

for other cases, where c is a number of code blocks, K_(r) is a size forcode block r, O_(CQI) is a number of CQI/PMI bits including CRC bits andN_(RE) is a number of REs determined as N_(RE)=M_(sc)^(PUSCH-initial)·N_(symb) ^(PUSCH-initial), where c, K_(r), M_(sc)^(PUSCH-initial) and N_(symb) ^(PUSCH-initial), β_(offset)^(PUSCH)=β_(offset) ^(CQI) for A-CSI sent via PUSCH without UL-SCH dataand 1 for other cases, and f_(c)(i)=f_(c)(i−1)+δ_(PUSCH,c)(i−K_(PUSCH))if accumulative CLPC is used, and f_(c)(i)=δ_(PUSCH,c)(i−K_(PUSCH)) ifabsolute CLPC is used where δ_(PUSCH,c)(i−K_(PUSCH)) is a TPC commandincluded in a DCI format scheduling a PUSCH or included in a DCI format3/3A. K_(PUSCH) is derived from a timeline between a slot of a PDCCHtransmission scheduling a PUSCH and a slot of a respective PUSCHtransmission.

FIG. 6 illustrates an example slot structure 600 for PUSCH transmissionaccording to embodiments of the present disclosure. An embodiment of theslot structure 600 shown in FIG. 6 is for illustration only. Otherembodiments may be used without departing from the scope of the presentdisclosure.

A slot 610 which includes a total of N_(symb) ^(UL) symbols 620 fortransmitting data information, UCI, or RS. Some slot symbols are usedfor transmitting DMRS 630. Each RB includes N_(sc) ^(RB) SCs and a UE isallocated M_(PUSCH) RBs 640 for a total of M_(sc)^(PUSCH)=M_(PUSCH)·N_(sc) ^(RB) SCs for a transmission BW. A last slotsymbol can be used to multiplex SRS transmissions 650 from one or moreUEs. For 2 slot symbols used for DMRS transmission, a number of slotsymbols available for data/UCI/DMRS transmission is N_(symb)^(PUSCH)=N_(symb) ^(UL)−2−N_(SRS), where N_(SRS)=1 when the last slotsymbol is used to transmit SRS and N_(SRS)=0 otherwise.

A hybrid slot includes a DL transmission region, a guard period region,and an UL transmission region, similar to a special SF. For example, aDL transmission region can contain PDCCH and PDSCH transmissions and anUL transmission region can contain PUCCH transmissions. For example, aDL transmission region can contain PDCCH transmissions and an ULtransmission region can contain PUSCH and PUCCH transmissions.

FIG. 7 illustrates an example transmitter structure 700 using OFDMaccording to embodiments of the present disclosure. An embodiment of thetransmitter structure 700 shown in FIG. 7 is for illustration only.Other embodiments may be used without departing from the scope of thepresent disclosure.

Information bits, such as DCI bits or data bits 710, are encoded byencoder 720, rate matched to assigned time/frequency resources by ratematcher 730, and modulated by modulator 740. Modulated encoded symbolsand DMRS or CSI-RS 750 are mapped to SCs 760 by SC mapping unit 765, anIFFT is performed by filter 770, a CP is added by CP insertion unit 780,and a resulting signal is filtered by filter 790 and transmitted by anradio frequency (RF) unit 795.

FIG. 8 illustrates an example receiver structure 800 using OFDMaccording to embodiments of the present disclosure. An embodiment of thereceiver structure 800 shown in FIG. 8 is for illustration only. Otherembodiments may be used without departing from the scope of the presentdisclosure

A received signal 810 is filtered by filter 820, a CP removal unitremoves a CP 830, a filter 840 applies an FFT, SCs de-mapping unit 850de-maps SCs selected by BW selector unit 855, received symbols aredemodulated by a channel estimator and a demodulator unit 860, a ratede-matcher 870 restores a rate matching, and a decoder 1180 decodes theresulting bits to provide information bits 890.

One characteristic of so-called 5G systems is that slot duration candepend on a service type. Additionally symbol duration or, equivalently,a sub-carrier spacing can depend on the service type. For example, forservices that can benefit from low latency the slot duration can be 0.1msec while for latency-tolerant services an overhead associated withpacket headers can be minimized by transmitting larger data TBs over alonger slot and a slot duration can be 0.5 msec or longer. Differentservices can also require different reliability requirements; forexample, ultra-reliable services can require a BLER of 0.1% or smallerwhile typical mobile broadband services can require a BLER of 1% orlarger.

As an NR RAT is introduced in an existing LTE network, it is highlylikely that at least for early deployments, both LTE and NR may need toco-exist in a same or in an overlapping spectrum. Spectrum sharing isthen required to support LTE and NR coexistence. Spectrum sharingmechanisms can depend on several factors including whether or not an LTEscheduler and an NR scheduler can perform coordinated scheduling andwhether or not a UE capable for operating with an NR RAT can alsooperate with an LTE RAT. Coordinated scheduling is typically possiblewhen an eNB scheduler for LTE and a gNB scheduler for NR are collocated,in such case even a same scheduler for LTE and NR can be possible, orconnected via a backhaul with materially negligible latency in order toexchange dynamic configurations over respective interfaces.Non-coordinated scheduling is typically required when conditions forcoordinated scheduling cannot be fulfilled. Also, LTE and NR coexistencecan depend on whether or not NR capable UEs are also LTE capable as,when this holds, NR capable UEs can perform initial access to a networkas LTE UEs.

Ultra reliable low latency communication (URLLC) poses significantchallenges in a network operation as corresponding data or controlinformation needs to be transmitted almost immediately and reliablyregardless of the existence of other ongoing transmissions over anassociated BW. The challenges are also different between DLtransmissions and UL transmission for URLLC. In the DL, a gNB cantransit URLLC service but puncturing, when necessary, other ongoingservice such as enhanced mobile broadband (eMBB) service. Even thoughthere is performance degradation in the reception reliability of eMBBdata TBs, including potentially a complete loss of one or more data codeblocks (CBs) of a data TB, a degradation in the reception reliability ofURLLC data TBs can be avoided as the gNB can avoid interference on URLLCtransmissions from other transmissions on the same carrier. Moreover,the gNB can mitigate the puncturing impact on eMBB data TBs byretransmitting punctured data CBs or by retransmitting the entire dataTB or by other means such as using an outer block code.

For UL URLLC transmissions initiated by respective UEs, it is morechallenging to ensure a desired reception reliability as suchtransmissions are decentralized and a serving gNB cannot generallyensure that a URLLC transmission from a UE may not be interfered fromone or more eMBB transmissions from first other UEs or from one or moreURLLC transmissions from second other UEs. For example, when a UEtransmits URLLC data over a BW, there can be one or more ongoing eMBBtransmissions over the BW or there can be one or more other URLLCtransmissions over the BW. Moreover, a URLLC transmission from a UE canoccur autonomously without a serving gNB knowing in advance of the URLLCtransmission. Consequently, means need to be provided for the gNB todetect the URLLC transmission and identify the associated UE.

FIG. 9 illustrates an example URLLC transmission 900 from a UE to a gNBaccording to embodiments of the present disclosure. An embodiment of theURLLC transmission 900 shown in FIG. 9 is for illustration only. Otherembodiments may be used without departing from the scope of the presentdisclosure.

An eMBB slot 910 includes seven eMBB symbols. A URLLC slot includes anumber of URLLC symbols with total duration equal to the duration of oneeMBB symbol 920. A first UE, UE1 930, and a second UE, UE2 940, transmitURLLC service in respective URLLC slots without interference from otherURLLC service in a corresponding transmission BW. A third UE, UE3 950,and a fourth UE, UE4 955, transmit URLLC service in a same URLLC slotand in respective BWs that at least partially overlap and thereforeURLLC transmissions from UE3 and URLLC transmissions from UE4 experiencemutual interference that degrades respective reception reliabilities.Also, when eMBB UEs transmit in the eMBB slot 910 over a BW that atleast partially overlap with a BW of URLLC transmissions during the eMBBslot, the transmission from a eMBB UE experiences mutual interferencewith transmissions from one or more URLLC UEs and all respectivereception reliabilities are degraded.

When a UE transmits to a serving gNB without the serving gNB havingconfigured the transmission from the UE, it can be challenging for theserving gNB to detect the transmission from the UE. The gNB needs toattempt to detect non-configured transmissions at applicable frequencyresources at each possible time slot and this can result to misseddetections and either require large operational complexity when variableMCS or RB allocation can apply for each transmission or penalizespectral efficiency when a fixed MCS or a fixed RB allocation apply foreach transmission. Therefore, there is a need to support LTE and NRcoexistence when an LTE scheduler and an NR scheduler cannot supportcoordinated scheduling for UEs operating with an LTE RAT and for UEsoperating with an NR RAT, respectively.

There is another need to support LTE and NR coexistence when an LTEscheduler and an NR scheduler can support coordinated scheduling for UEsoperating with an LTE RAT and for UEs operating with an NR RAT,respectively.

There is another need to optimize support for LTE and NR coexistencewhen UEs capable of operating with an NR RAT are also capable foroperating with an LTE RAT.

There is a need for a gNB to multiplex, over a common set of frequencyresources and during a same time, control transmissions to UEssupporting a first service type using a first symbol duration for datatransmission and to UEs supporting a second service using a secondsymbol duration for data transmissions.

There is another need for a UE to inform a gNB of a UE identity and ofparameters for a transmission that is not configured by the gNB.

There is another need to support a transmission for a first service typeduring a first time slot without interfering with a transmission for asecond service type during a second time slot that includes the firsttime slot.

There is another need to support a transmission for a first service typeduring a first time slot without interfering with another transmissionfor the first service type during the first time slot.

Finally, there is another need for a gNB to reduce a probability ofcollision between a non-configured transmission and a configuredtransmission and to reduce a probability of collision between twonon-configured transmissions.

The present disclosure relates to supporting LTE and NR coexistence whenan LTE scheduler and an NR scheduler cannot support coordinatedscheduling for UEs operating with an LTE RAT and for UEs operating withan NR RAT, respectively. The disclosure also relates to supporting LTEand NR coexistence when an LTE scheduler and an NR scheduler can supportcoordinated scheduling for UEs operating with an LTE RAT and for UEsoperating with an NR RAT, respectively. The disclosure further relatesto optimizing support for LTE and NR coexistence when UEs capable ofoperating with an NR RAT are also capable for operating with an LTE RAT.

In some embodiments, the coexistence of LTE operation with NR operationis considered when an LTE scheduler and an NR scheduler areuncoordinated and a fixed partition of time-frequency resources on acell applies over a period of SFs such as 10 SFs or 40 SFs. LTEoperation and NR operation are restricted to occur only on correspondingLTE time-frequency resources and NR time-frequency resources. Mechanismsto support such coexistence need to be backward compatible for LTE UEsas LTE UEs are already deployed and changes to existing signalingmechanisms cannot be applicable. In the following, information relatedto signaling from an eNB to LTE UEs that is known by a gNB orinformation related to signaling from a gNB to NR UEs that is known byan eNB is assumed to be exchanged over respective interfaces between theeNB and the gNB and between the gNB and the eNB.

When an LTE scheduler and an NR scheduler cannot coordinate schedulingassignments per SF, such as for example when the schedulers need tooperate independently due to being non-collocated and connected viainterfaces of a backhaul with material latency, a dynamic BW utilizationbetween NR operation and LTE operation is not practically feasible and asemi-static one can be preferable. A semi-static BW partition for acell/carrier can be based on non-instantaneous traffic characteristicsfor NR UEs and LTE UEs. For example, an LTE scheduler and an NRscheduler can exchange buffer status reports for DL traffic and ULtraffic for served LTE UEs and NR UEs, respectively, and a coordinatingunit can indicate a BW partition for LTE operation and for NR operation.A resource partition can also extend to the time domain by configuringMBSFN SFs or ABS SFs for LTE operation.

For a cell BW partition in a manner that is compatible with existing LTEoperation, the LTE scheduler can re-configure a cell BW by paging LTEUEs for a SI update and indicating a new LTE DL cell BW in an LTE MIB ora new LTE UL cell BW in an LTE SIB2. For example, for a DL cell BW of 20MHz, an LTE MIB can indicate an LTE DL cell BW of 10 MHz during a firsttime period and, after a relative increase of NR DL traffic or adecrease of LTE DL traffic, indicate an LTE DL cell BW of 5 MHz during asecond time period. An NR DL cell BW is then 10 MHz during the firsttime period and 15 MHz during the second time period. In this manner, itis possible to minimize use of a DL cell BW for LTE operation and usethe DL cell BW primarily for NR operation. For example, for a DL cell BWof 20 MHz, an LTE cell BW of 1.4 MHz can be indicated by an LTE MIB andparts or all of a remaining 18.6 MHz of BW can be allocated to NRoperation. Then, the LTE DL cell BW can be used to providesynchronization, PBCH transmission, and communication support to LTE UEsor to NR UEs with capability to operate with LTE RAT, while all otherfunctionalities can be provided by ab NR RAT on the NR DL cell BW.

When a gNB and NR UEs need to be informed of an LTE DL cell BW or of anLTE UL cell BW, as this can affect rate matching of DL transmissions toNR UEs to LTE signaling, such as CRS or CSI-RS, as is discussed insubsequent embodiments of this disclosure, this information can beprovided to NR UEs by an NR MIB, or an NR SIB (or extended MIB), or byRRC signaling, or through a DCI format scheduling DL transmissions to NRUEs or informing of resources that DL transmissions to NR UEs are ratematched around. It is also possible that NR UEs can operate as LTE UEsand obtain the LTE DL cell BW through an LTE MIB.

FIG. 10 illustrates an example adaptation 1000 of an LTE DL cell BW andassociated signaling to LTE UEs and NR UEs according to embodiments ofthe present disclosure. An embodiment of the adaptation 1000 shown inFIG. 10 is for illustration only. Other embodiments may be used withoutdeparting from the scope of the present disclosure.

An LTE scheduler and an NR scheduler can exchange information viarespective interfaces, such as for example buffer status reports for DLtraffic, for LTE UEs and NR UEs, respectively, and an update for anallocation of a DL cell BW between an LTE DL cell BW and an NR DL cellBW can then be determined by a BW allocation controller. For example,during a first time period and for a DL cell BW of 20 MHz, an LTE MIBindicates 1050 an LTE DL cell BW of 5 MHz 1005. An NR MIB or an NR SIB(or NR enhanced MIB) also indicates 1010 an NR DL cell BW of 15 MHz thatis equally divided in two parts of 7.5 MHz on each side of the DL cellBW 1012, 1014. Depending on a numerology (such as a symbol duration or aSC spacing and a CP length) used for transmissions to LTE UEs and on anumerology used for transmissions to NR UEs, guard bands may or may notbe needed between an LTE DL cell BW and an NR DL cell BW. For example,when a same DL numerology is used between LTE and NR, guard-bands arenot used; otherwise, guard-bands can be used (LTE numerology ispredetermined, NR numerology can be indicated by MIB, SIB, orUE-specific higher layer signaling). After an update for a DL cell BWpartition is determined by the controller, for example from 5 MHz to 10MHz for an LTE DL cell BW, LTE UEs can be paged by an eNB and beinformed by an LTE MIB 1020 of an LTE DL cell BW of 10 MHz 1025. NR UEscan also be paged by a gNB and be informed by an NR MIB 1030 of an NR DLcell BW of 10 MHz or NR UEs can be informed, explicitly or implicitly,of an LTE DL cell BW of 10 MHz in a DL cell BW of 20 MHz through DL DCIformats scheduling DL transmissions to NR UEs. Then, NR UEs candetermine that a 5 MHz BW is available for an NR DL cell BW on each sideof the DL LTE cell BW 1032, 1034.

Several approaches can apply for indicating an NR DL cell BW. In a firstexample, an NR UE is informed, for example by (UE-specific or UE-common)higher layer signaling from a gNB, of a DL cell BW and of an LTE DL cellBW in the form of a reserved BW. Then, an NR UE can determine an NR DLcell BW as the remaining of the DL cell BW after excluding the reservedLTE DL cell BW. In a second example, in order to reduce a number ofrequired bits, a DL cell BW and a reserved LTE DL cell BW can be jointlyindicated subject to the LTE DL cell BW being smaller than the DL cellBW. In a third example, an NR UE is configured, for example by higherlayer signaling, one or more BW parts of the DL cell BW that form the NRDL cell BW. The NR DL cell BW can be equally divided between the twoends of the DL cell BW. For a semi-static partition of a DL cell BWwhere an NR scheduler does not schedule DL transmissions to NR UEs inthe LTE DL cell BW, NR UEs do not need to know that the LTE DL cell BWis used for LTE DL transmissions. However, as is subsequently described,for a dynamic partition of a DL cell BW where an NR scheduler schedulesDL transmissions to NR UEs in the LTE DL cell BW, it can be beneficialfor NR UEs to be aware that the additional DL cell BW is an LTE DL cellBW. Then, NR UEs can be informed of additional parameters for LTEtransmissions such as a number of CRS antenna ports or a CSI-RSconfiguration as reserved resources where DL transmissions to NR UEs arerate matched around. For example, LTE can have 1, 2, or 4 CRS antennaports and a number can be indicated by 2 bits. For example, 5 bits canbe used to indicate a CSI-RS configuration in LTE.

For a partition of time resources in a manner that is compatible toexisting LTE operation, an MBSFN SF configuration or an ABS SFsconfiguration can apply for LTE operation. For example, 10 bits or 40bits can be used for a MBSFN or ABS SFs configuration in LTE. For a TDDsystem having an UL/DL configuration, UL SFs without mapped timing forHARQ-ACK transmissions from LTE UEs, such as a third SF and an eight SFfor UL/DL configuration 0, can be switched to DL SFs. Additional UL SFscan be switched to DL SFs for NR operation when an eNB does not schedulePDSCH transmissions to LTE UEs in DL SFs having an associated HARQ-ACKtiming on the UL SFs and such DL SFs can also be used for NR operation.The LTE scheduler can then ensure absence of other UL transmissions inthose UL SFs. A coordinating entity, such as a time resource controller,can indicate to an NR scheduler an availability of some or all of theconfigured MBSFN SFs or ABS SFs or DL SFs and UL SFs for a TDD system. Acombination of FDM and TDM of LTE time-frequency resources and NRtime-frequency resources can also apply.

Although DL transmissions to NR UEs can occur in MBSFN SFs or ABS SFs,such DL transmissions need to be rate-matched (or punctured) aroundsub-carriers or symbols used for CRS transmission and, for the case ofMBSFN SFs, avoid the first one or two SF symbols that can be used for DLcontrol signaling to LTE UEs. As a number of SF symbols used for DLcontrol signaling to LTE UEs can vary per SF and an NR scheduler cannotbe assumed to know this number prior to scheduling DL transmissions toNR UEs, for example when the NR scheduler and the LTE scheduler are notparts of a joint scheduler, the NR scheduler either needs to assume thata maximum number of SF symbols are used for DL control signaling to LTEUEs or a constraint on the maximum number can be enforced by acoordinating entity to the LTE scheduler and be informed to the NRscheduler. For example, without any coordination, an NR scheduler canassume that the maximum of two SF symbols are used for DL controlsignaling to LTE UEs in an MBSFN SF and three SF symbols are used innormal (non-MBSFN) SFs. For example, with coordination, a controller canlimit a number of SF symbols used for DL control signaling to LTE UEs tobe one in MBSFN SFs or two in normal SFs and inform the NR schedulerthat all symbols in a MBSFN SF or in a normal SF except for the firstone or first two ones, respectively, are available for DL transmissionsto NR UEs. NR SI or UE-specific RRC signaling can inform NR UEs of astarting SF symbol for receptions of PDCCH transmissions or PDSCHtransmissions in MBSFN SFs and of a starting SF symbol for receptions ofPDCCH transmissions or PDSCH transmissions in non-MBSFN SFs. A gNB canobtain this information from an eNB through an interface.

When NR slot duration, such as 0.5 msec, is smaller than a SF duration,such as I msec, a first NR slot needs to be shortened to avoidinterfering with a DL control region of two symbols in an LTE MBSFN SFwhile a following second NR slot does not need to be shortened. Toenable a uniform NR slot duration, an NR slot can have a smaller numberof symbols when NR slots are within a MBSFN SF. For example, for a MBSFNSF of 14 symbols and an NR slot of 7 symbols, a shortened NR slot of 6symbols can be used and two shortened NR slots can exist in a MBSFN SF.For example, for a MBSFN SF of 14 symbols and an NR slot of 14 symbols,a shortened NR slot of 12 symbols can be used. NR slot duration in theUL can be maintained at 7 symbols or 14 symbols. Similar considerationscan also apply for other NR slot durations.

FIG. 11 illustrates an example use of LTE MBSFN SFs 1100 as NR slotsaccording to embodiments of the present disclosure. An embodiment of theuse of LTE MBSFN SFs 1100 shown in FIG. 11 is for illustration only.Other embodiments may be used without departing from the scope of thepresent disclosure.

A coordinating entity can determine a MBSFN SF (or ABS SF) configurationfor LTE operation and configure a subset of MBSFN SFs as slots for NRoperation. An LTE SIB, such as a SIB2, indicates a MBSFN SFconfiguration while an NR SIB indicates a MBSFN SF configuration thatcan be a subset of the one indicated by the LTE SIB. A set of SFsincludes normal SFs 1110, MBSFN SFs for LTE 1120, and MBSFN SFs for NR1130. The NR SIB can also inform an NR UE of a slot structure thatexcludes symbols used for DL control signaling to LTE UEs 1140 in MBSFNSFs and in normal SFs or for adjusting a length of an NR slot, forexample from 7 symbols to 6 symbols or from 14 symbols to 12 symbols, inorder to provide 2 NR slots, 1150 and 1155, with an equal number ofsymbols in MBSFN SFs.

When only MBSFN SFs are used for NR slots and NR UEs do not have a sameDL timing as LTE UEs, for example when an eNB and a gNB are notcollocated, at least one MBSFN SF is maintained as an NR slot in orderfor an NR gNB to transmit synchronization and SI signals. This alsoholds when not all NR UEs can operate with the LTE RAT. When DLtransmissions to LTE UEs and NR UEs use a same numerology, it is alsofeasible for an NR gNB to use normal SFs to transmit synchronization andSI signals. An impact to LTE UEs can be avoided by the LTE scheduler(LTE eNB) being informed in advance through an interface from acoordinating entity of the time-frequency locations used by the gNB fortransmission of synchronization and SI signals including controlresources used for scheduling SI. Several different realizations of thisinformation exchange can exist; for example, an eNB can directlyindicate to a gNB through an interface the time-frequency locations orthe reverse. The time-frequency locations for transmission ofsynchronization and SI signals to NR UEs may avoid the, fixed in the LTEsystem specifications, time-frequency locations used for transmission ofCRS, primary synchronization signal/secondary synchronization signal(PSS/SSS), and PBCH to LTE UEs. The LTE scheduler can then avoidscheduling/configuring other transmissions to LTE UEs on thetime-frequency locations used by a gNB to transmit synchronization andSI signals. For example, time locations for a gNB to transmitsynchronization and SI signals may avoid symbols in a first SF or in asixth SF per frame, such as the first 3 symbols, that can be used by aneNB to transmit DL control signaling, and the fifth, eighth, ninth, andtwelfth symbols that can be used by an eNB to transmit CRS in normalSFs. Frequency locations may avoid the middle 72 SCs at least in symbolsthat can be used by an eNB to transmit synchronization or SI signals inthe first SF per frame.

For UL transmissions from NR UEs, any UL SF can be used and the NRscheduler can be further informed though an interface of resources,including no resources, in each such UL SF that can be used for PUCCH orPRACH or SRS transmissions from LTE UEs. For example, 2 bits canindicate a SRS configuration, 5 bits can indicate a PRACH configuration,and a predetermined number of bits, such as 5 bits, can indicate anumber of RBs reserved for PUCCH transmissions from each size of an ULBW. A BW controller can allocate remaining resources for LTE operationor for NR operation.

In some embodiments, the coexistence of LTE operation with NR operationis considered when an LTE scheduler and an NR scheduler are coordinated.Then, with some exceptions for predetermined time-frequency resourcesfor LTE signaling such as for CRS, PSS/SSS and PBCH, all time-frequencyresources on a cell can be dynamically used for NR operation per SF.Collisions among transmissions to or from LTE UEs and NR UEs can beavoided through coordination of an LTE scheduler and an NR scheduler.For example, the LTE scheduler and the NR scheduler can be coordinatedby a same scheduling entity or be components of a same scheduler.

Similar to LTE and NR coexistence through a semi-static partition oftime-frequency resources, coexistence is transparent to LTE UEs that aredesigned to operate without coexistence with an NR RAT also in case ofdynamic resource partition. For NR operation, in order to improveresource utilization and make coexistence with LTE feasible in practice,a gNB needs to inform NR UEs for a presence of LTE signaling inrespective time-frequency resources.

For synchronization signals and PBCH transmissions that exist inpredetermined time-frequency resources, no additional signaling to NRUEs is needed as NR UEs can determine those time-frequency resourcesfrom NR SI that informs of: coexistence with an LTE RAT (1 bit—can alsobe implicit through a predetermined configuration of other parameters inNR MIB or NR SIB); a SFN and a SF number within a frame (synchronizationsignals and PBCH transmissions are in predetermined SFs per frame); anda DL cell BW (synchronization signals and PBCH transmissions are in themiddle 6 RBs of the DL cell BW).

In case an LTE eNB support repetitions of synchronization or broadcastsignaling in predetermined resources, this information can also beprovided to a gNB and to NR UEs by the gNB through NR SI signaling.Moreover, NR SI can inform, for example using 2 bits, a number of CRSantenna ports and a cell identity associated with LTE operation in orderfor an NR UE to determine subcarriers used for CRS transmission as beingreserved resources.

For LTE signaling that is not present but is configured by an eNBthrough SI signaling, corresponding configurations need to also beprovided to a gNB and to NR UEs by the gNB through respective SIsignaling or higher layer UE-specific signaling. Such configurationsinclude: an UL carrier BW (UE-common configuration); an UL/DLconfiguration in case of a TDD system (UE-common configuration); anMBSFN SF configuration and a ABS configuration (UE-commonconfiguration); CSI-RS configuration, including NZP CSI-RS and ZP CSI-RS(UE-common or UE-specific configuration); SRS configuration (for maximumtransmission BW and SFs per frame-UE-common configuration); PRACHconfiguration (for transmission BW and SFs per frame-UE-commonconfiguration); RBs and SFs per frame for EPDCCH, MPDCCH, PUCCH, and SPStransmissions (UE-specific configuration); and a maximum number of SFsymbols used for PDCCH transmissions (UE-common configuration can beseparate for normal SFs and MBSFN SFs—dynamic).

Some of the above configurations, such as the RBs for SPS PDSCH, EPDCCH,or MPDCCH transmissions, are UE-specific while other configurations,such as the MBSFN SF configuration or the PRACH configuration, areUE-common. Further some configurations, such as a number of SF symbolsused for LTE PDCCH transmissions, can be dynamic per SF unless thenumber of SF symbols used for LTE PDCCH transmission is implicitlyconfigured by indicating a maximum number of symbols for PHICHtransmission in the LTE-MIB. When LTE DL transmissions and NR DLtransmissions are scheduled by a common scheduler or by coordinatedschedulers, a number of SF symbols used for LTE PDCCH transmissions, orequivalently a start symbol for DL transmissions to NR UEs, can bedynamically informed to NR UEs per applicable slot either through aUE-common DCI format or through a DCI format scheduling a PDSCHtransmission to an NR UE, otherwise, a number of LTE SF symbols used forLTE PDCCH transmissions in normal SFs or MBSFN SFs can be signaled in anNR SI or can be assumed to be a maximum one such as 3 SF symbols.

When NR UEs can process (understand) configurations for LTE UEs, abovereferenced configurations that are UE-common can be informed to NR UEsby a gNB through NR SI in a same manner as they are informed to LTE UEsby an eNB through LTE SI. As is subsequently discussed, when NR UEs canoperate as LTE UEs, NR UEs can establish an RRC connection with an eNBprior to declaring their capability to operate as NR UEs. In such case,NR UEs can synchronize to the eNB and obtain LTE SI for UE-commonconfigurations from the eNB.

A gNB can inform NR UEs of LTE configurations that are UE-specific by NRSI as a super-set of the UE-specific configurations. For example, when afirst LTE UE is configured RBs with indexes 0 through 3 for receivingEPDCCH transmissions and a second UE is configured RBs with indexes 8through 11 for receiving EPDCCH transmissions, an NR UE can be informedby NR SI or by LTE SI that RBs with indexes 0 through 3 and 8 through 11are reserved resources (as they are used for EPDCCH transmissions to LTEUEs). For example, when a first LTE UE is configured with a first CSI-RSconfiguration and a second UE is configured with a second CSI-RSconfiguration, NR SI can signal that both first CSI-RS configuration andsecond CSI-RS configuration are reserved resources (as they are used forLTE UEs). RBs used for LTE PUCCH transmissions can vary per SF,depending for example on a number of resources used for HARQ-ACKtransmissions per SF, and an NR SI can indicate a number of RBs fromeach side of the UL cell BW that NR UEs can assume as being unavailable(reserved resources) for transmissions from NR UEs (and as being usedfor PUCCH transmissions from LTE UEs) when LTE UEs and NR UEs share asame UL cell BW. NR SI can also indicate a combination of time-frequencyresources that NR UEs may assume as being unavailable (reservedresources) for transmissions to or from NR UEs, for example byindicating a set of RBs per SF within a number of frames such as one orfour frames. For example, a set of RBs can be indicated as used for SPStransmissions from LTE UEs in a first SF of a frame but not in remainingSFs of the frame. When NR UEs can operate as LTE UEs, the aboveconfigurations can also be included in LTE SI, such as in SIB2, insteadof transmitting a separate NR SI.

When NR UEs cannot process (understand) configurations for LTE UEs, oreven when NR UEs can process configurations for LTE UEs, NR SI or LTE SIcan indicate a set of time-frequency resources that are unavailable(reserved resources) for transmissions to or transmissions from NR UEswithout indicating what channels or signals associated with LTE UEs usethose resources. For example, NR SI or LTE SI can indicate a set of RBsof a DL cell BW or of an UL cell BW as being unavailable and this can beapplicable to all SFs. For example, NR SI or LTE SI can indicate a setof RBs of a DL cell BW or of an UL cell BW as being unavailableseparately per SF in a number of SFs such as per SF in a frame or per SFin four frames and this enables, for example, indication for middle 6RBs as being unavailable only in SFs where PBCH is transmitted. Forexample, NR SI or LTE SI can indicate a set of DL SF symbols or a set ofUL SF symbols as being unavailable separately per SF in a number of SFssuch as per SF in one NR frame or per SF in four NR frames. An NR UE,upon receiving a scheduling assignment to receive or a scheduling grantto transmit in time-frequency resources that at least partially overlapwith time-frequency resources indicated by NR SI or LTE SI as beingunavailable, can rate match or puncture the respective reception ortransmission.

Coexistence of LTE and NR operation on the UL can generally be supportedby scheduler implementation. When an LTE UL cell BW is definedseparately from an UL cell BW, frequency resources that are notavailable to NR UEs (reserved resources), or equivalently frequencyresources that are available to NR UEs, can be signaled in an NR SI orby UE-specific higher layer signaling in terms of RBs. For example, anNR SI can signal a number of RBs for an LTE UL cell BW (reserved RBs)relative to an UL cell BW and, to minimize SI overhead as LTE PUCCHresources are located on each end of the LTE UL cell BW, the NR SI cansignal only a number of RBs relative to one end of the LTE UL cell BW.NR UEs can interpret that a same number of RBs is also unavailable(reserved) from the other end of the LTE UL cell BW or those RBs canalso be explicitly configured to NR UEs, for example by SI or byUE-specific higher layer signaling, as reserved RBs. For example, for anUL cell BW of 100 RBs, an NR SI can signal an UL cell BW of 50 RBs, suchas the middle 50 RBs, and also signal that 10 RBs are unavailable(reserved). An NR UE can determine that RBs with indexes 0 through 4 andRBs with indexes 46 through 50 are unavailable for transmissions fromthe NR UE. UL SFs that are not available for NR transmissions can besignaled in terms of SFs. For example, a bit-map of 10 bits can indicate(available for LTE transmissions and available for NR transmissions) ULSFs per frame. Instead of signaling unavailable UL time-frequencyresources, an NR SI can signal available time-frequency resources in acomplementary manner. To avoid collisions with SRS transmissions fromLTE UEs, an NR SI can signal a set of SFs per number of frames where NRUEs may not transmit on a last SF symbol (SRS configuration), or an ULDCI scheduling a PUSCH transmission from an NR UE can include a 1-bitfield indicating whether or not the NR UE may transmit PUSCH in one ormore last SF symbols or can indicate a duration for the PUSCHtransmission that excludes the last one or more SF symbols.

When an NR UE does not first establish a RRC connection as an LTE UEthrough a use of LTE synchronization signals, SI, and random accessprocedure, corresponding functionalities need to be separately providedby a gNB. This is applicable to either dynamic resource sharing with LTEin case of coordinated schedulers or to semi-static resource sharing incase of uncoordinated schedulers. NR synchronization signals and firstNR SI (NR MIB) need to be transmitted prior to second NR SI (NR SIB)informing NR UEs of available DL frequency resources. DL frequencyresources for the NR synchronization signals and the first NR SI, suchas a PBCH conveying an NR-MIB, can include RBs of a DL cell BW otherthan the middle 6 RBs used for transmitting LTE synchronization signalsand PBCH. For a more robust NR and LTE coexistence that avoids anylong-term scheduling impact to LTE UEs, such as an inability tosemi-statically assign RBs for SPS PDSCH, EPDCCH, or MPDCCHtransmissions, and avoids any forward compatibility restrictions to LTEoperation, DL frequency resources for the NR synchronization signals andthe first NR SI not only need to avoid the middle 6 RB of the DL cell BWbut also need to avoid all RBs corresponding to the LTE DL cell BW.Therefore a frequency location of synchronization signals and first SIsignals for NR UEs needs to be flexible, for example to avoid an LTE DLcell BW that can have a varying number of RBs.

NR PBCH transmissions can occur in a same BW as the BW for transmissionof NR synchronization signals or in a different BW that can bedetermined by information included in the NR synchronization signals. NRPBCH can convey an NR MIB that can include an indication of an NR DLcell BW (DL cell BW excluding the LTE DL cell BW). The NR DL cell BW canbe indicated by indicating a DL cell BW, such as 20 MHz, and alsoindicating an excluded DL cell BW (the LTE DL cell BW), such as 10 MHz,that NR UEs interpret as being located in the middle of the 20 MHz. TheDL cell BW and the LTE DL cell BW can be separately indicated or, inorder to reduce a number of required bits, be jointly indicated subjectto the LTE DL cell BW being smaller than the DL cell BW. The NR DL cellBW can also be directly indicated, without considering an LTE DL cellBW, by indicating, for example by NR SI, additional BW relative to theBW of the transmission of NR synchronization signals or PBCH.

Once an NR UE determines an NR DL cell BW, the NR UE can monitor PDCCHon one or multiple parts of the NR DL cell BW for scheduling PDSCH thatconveys other SI. The PDCCH can be monitored at least in slots where theNR synchronization signals or the NR PBCH are transmitted. Instead ofincluding an indication of a DL cell BW and of NR DL cell BW, the NR MIBcan include scheduling information, such as RBs and TB size for NR SItransmission or RBs for PDCCH transmissions scheduling NR SI, for an NRSI and the NR DL cell BW can be conveyed by the NR SI. The RBs of the NRSI or of the PDCCH transmission scheduling the NR SI can be indicatedrelative to the RBs for transmission of NR synchronization signals or NRPBCH and can be, for example, symmetrically placed or placed with anoffset from a set of predetermined offsets. For example, an offset canbe relative to the middle of the BW used for transmission of NR PBCH orsynchronization signals. A similar indication can apply for slots orslot symbols and can be relative to a last symbol used for transmissionof synchronization signals and NR PBCH. The LTE DL cell BW can beavailable to NR UEs in at least some of the SFs indicated as MBSFN SFsto LTE UEs and an NR SI can indicate such MBSFN SFs in addition toindicating MBSFN SFs.

To expedite a synchronization and SI acquisition process, an NR UE thatis also capable of operating as an LTE UE can attempt to detect both LTEsynchronization and MIB/SIB signals and NR synchronization and MIB/SIBsignals. When an NR UE detects LTE synchronization and MIB/SIB signals,the NR UE can determine an LTE DL cell BW and can be informed by LTE SIwhether there is an NR DL cell BW. The NR UE can then proceed to detectNR synchronization signals in frequency locations that are, for example,outside the LTE DL cell BW and expedite the associated process forestablishing an RRC connection for NR operation.

FIG. 12 illustrates an example process 1200 for an NR UE to synchronizeand obtain SI on a cell supporting LTE and NR coexistence according toembodiments of the present disclosure. An embodiment of the process 1200shown in FIG. 12 is for illustration only. Other embodiments may be usedwithout departing from the scope of the present disclosure.

On a cell having a DL cell BW 1210, an NR UE detects NR synchronizationsignals having a predetermined BW at step 1220. The synchronizationsignals are transmitted in one or more symbols of a SF 1230 and the BWlocation of the synchronization signal does not overlap with the middle6 RBs 1240 of the DL cell BW. After detecting the NR synchronizationsignals, the NR UE detects an NR BPCH at step 1250 that is transmittedin other symbols of the SF and over the same BW as the NRsynchronization signals 1260. An NRNR DL control signaling 1270 can betransmitted in NR DL cell BW that does not include transmission of NRsynchronization signals and NR PBCH. After detecting the NR MIB, an NRUE can determine the NR DL cell BW and proceed with a detection of NRPDCCH scheduling PDSCH that convey NR SI at step 1280 and aretransmitted in a BW and symbols indicated respectively in NR MIB throughan offset relative to the BW of synchronization signals and NR MIB andan offset relative to a last symbol of synchronization signals and NRMIB transmissions. The NR UE can then obtain information for an NR ULcell BW and for configurations for DL transmissions and for ULtransmissions on the LTE cell BW and on the NR cell BW at step 1290.

FIG. 13 illustrates an example structure 1300 for LTE and NR coexistencein a DL cell BW according to embodiments of the present disclosure. Anembodiment of the structure 1300 shown in FIG. 13 is for illustrationonly. Other embodiments may be used without departing from the scope ofthe present disclosure.

When schedulers for NR DL transmissions and for LTE DL transmissions arecoordinated, LTE DL cell BW can be used for NR transmissions. However,NR DL cell BW cannot be used for LTE transmissions at least for UEsupporting existing LTE functionalities. DL control signaling for LTEUEs is transmitted over the LTE DL cell BW 1310 and can have a differentduration than DL control signaling for NR UEs that is transmitted overan NR DL cell BW 1320, 1325. An NR UE can be informed of the durationfor LTE DL control signaling either through a UE-common DCI format orthrough a UE-specific DCI format such as for example a DCI formatscheduling a PDSCH transmission to the NR UE and the NR UE can startPDSCH reception after a last symbol for LTE DL control signaling. NR UEscan be scheduled PDSCH transmissions on the NR DL cell BW but also onthe LTE DL cell BW 1340 when LTE UEs are scheduled PDSCH transmissionsonly in a part of the LTE DL cell BW 1340. When an NR transmission slotduration is smaller than an LTE SF duration, such as for example when anNR slot duration is 0.5 msec while an LTE SF duration is I msec,multiple NR transmission slots can exist within an LTE SF. In a secondtransmission slot for NR UEs during an LTE SF, NR DL control signalingcan be transmitted either only in the NR DL cell BW or also includeavailable LTE DL cell BW when there is a UE-common DCI formattransmission in the previous NR slot that informs of a number of symbolsfor LTE DL control signaling in the LTE SF 1350. The tradeoffs are thatthe former approach is robust to miss-detection errors of the UE-commonDCI format in the previous NR transmission slot and maintains a samestructure for the DL control signaling regardless of an availability ofan LTE DL cell BW for NR transmissions while failing to utilize anavailable LTE DL cell BW for NR DL control signaling. An NR UE receivinga PDSCH transmission in part of an LTE DL cell BW needs to be aware of anumber of CRS antenna ports used by the LTE eNB and of a respective cellidentity and of CSI-RS configurations in the SF in order to rate matchor puncture the PDSCH reception in corresponding SCs. This informationof reserved resources can be provided to the NR UE by NR SI or byUE-specific higher layer signaling. An NR UE needs to also be aware ofthe SF number as this can determine presence of LTE synchronizationsignals and PBCH transmissions and corresponding rate matching orpuncturing of sub-carriers associated with a PDSCH transmission can thenalso apply.

In some embodiments, a UE capable of operating either as an LTE UE or asan NR UE can dynamically switch an operation mode per SF. Additionally,a cell supporting LTE UEs and NR UEs can dynamically switch a use of aDL cell BW to serve only NR UEs or to serve both NR UEs and LTE UEs andcan dynamically switch a use of an UL BW to serve only NR UEs or toserve only LTE UEs or both. This can be beneficial when DL traffic or ULtraffic can vary materially per SF. For example, for operation in smallcell environments where a small number of UEs, such as one to three UEs,is scheduled per SF and with high probability the UEs can happen to beonly NR UEs or only LTE UEs.

A UE capable of operating either as an LTE UE or as an NR UE canestablish an RRC connection with an LTE eNB as an LTE UE. The UE candeclare to the eNB the UE's capability to operate with the NR RAT, forexample by using an NR-specific PRACH resource (indicated by SI), or inMsg3 of a random access process, or by higher layer signaling afterestablishing an RRC connection with the eNB. When all NR UEs are capableof operating both as LTE UEs and as NR UEs, at least for establishing anRRC connection with an eNB, a gNB does not need to transmit NRsynchronization signals or SI signals such as NR PBCH or NR SIBs and anNR UE can perform a random access procedure as an LTE UE. Uponestablishing an RRC connection, or prior to establishing an RRCconnection, an NR capable UE can be informed of additional available NRDL cell BW or NR UL cell BW that is not visible to UEs capable ofoperating only as LTE UEs. For example, for a DL cell BW of 20 MHz, anLTE MIB can indicate an LTE DL cell BW of 10 MHz for LTE-only capableUEs and NR-capable UEs can be informed of an existence of an additional10 MHz of NR DL cell BW that is symmetrically placed, in two BWcomponents of 5 MHz each, around the 10 MHz LTE DL cell BW indicated bythe LTE MIB. The NR UEs can be informed of the NR DL cell BW or of theNR UL cell BW either through spare bits in the LTE MIB, or through anLTE SIB such as a SIB2, or by UE-specific RRC signaling, or by NR SI. NRUEs can also be configured by system specification to monitor adifferent SI-RNTI than LTE UEs, for example a SI-RNTI value for NR UEscan be different than the SI-RNTI value of 65535 (0xFFFF) for LTE UEs.

An NR UE can differentiate the NR UE's operation relative to an LTE UEafter establishing an RRC connection with an eNB but can also maintainoperational commonalities with an LTE UE. For example, an NR UE canmaintain the following LTE functionalities. In one example, the NR UEmaintains use of a CRS transmitted from an eNB only on the LTE DL cellBW to perform RSRP measurements for mobility and UL power control (a CRStransmission power can be provided by NR SI) or for receiving PDSCH witha CRS-based transmission mode while a gNB does not transmit CRS in theNR DL cell BW. In another example, the NR UE maintains PCFICH detectionper SF to determine a number of symbols for DL control signalingtransmission to LTE UEs. In yet another example, the NR UE maintainsPDCCH monitoring on the LTE DL cell BW according to the following twodesign alternatives.

A PDCCH transmission scheduling a PDSCH transmission to an NR UE or aPUSCH transmission from an NR UE can be located either on the LTE DLcell BW or on the NR DL cell BW in order to balance DL control signalingoverhead between the LTE DL cell BW and the NR DL cell BW and improveresource utilization. According to a capability for a number of PDCCHdecoding operations per SF, an NR UE can be configured a first set ofPDCCH candidates for respective CCE aggregation levels on the NR DL cellBW and a second set of PDCCH candidates for respective CCE aggregationlevels on the LTE DL cell BW. For example, the first set of candidatescan be used for scheduling NR transmissions using a first DCI formatsize on the NR cell while the second set of candidates can be used forscheduling LTE transmissions using a second DCI format size on the NRcell for the UE. The partitioning of a number of PDCCH decodingoperations a UE can perform per slot or SF can be indicated, forexample, to the gNB by the eNB. The eNB or the gNB can then respectiveconfigure to the NR UE a first number of LTE PDCCH decoding operationsper LTE CCE aggregation level per LTE cell and per LTE DCI format sizeand a second number of NR PDCCH decoding operations per NR CCEaggregation level per NR cell and per NR DCI format size. When there aremultiple NR slots within a SF, an NR UE can operate with all PDCCHcandidates being located on the NR DL cell BW for each NR slot otherthan a first NR slot per SF, or be configured with a third number of NRPDCCH decoding operations per NR CCE aggregation level per NR cell andper NR DCI format size when the UE does not perform LTE PDCCH decodingoperations. Therefore a configuration for a number of PDCCH decodingoperations for a UE to perform for PDCCH transmissions from a gNB can betime varying.

On an NR DL cell BW, an NR UE can operate with one or more of thefollowing characteristics: without presence of CRS; with variable NRtransmission duration, for example ranging from a sub-multiple of a SFin a number of SF symbols such as 7 SF symbols, to a multiple of the SFin a number of SF symbols such as 28 SF symbols; without presence of DLcontrol region at the beginning of at least some NR slots; withouttransmission of PCFICH or PHICH; and with independent configurations ofMBSFN SFs or ABS SFs.

An NR UE can be scheduled reception for a PDSCH transmission in a BWthat includes RBs both from the LTE DL cell BW and the NR DL cell BW.Rate matching, or puncturing, can apply to SCs of the PDSCH transmissionlocated in the LTE DL cell BW and used for default LTE transmissionssuch as CRS, or PSS/SSS, or PBCH transmission and the same can apply toSCs used for configured LTE transmissions when such SCs are informed toNR UEs though SI or UE-specific higher layer signaling. A resourceallocation field in DCI formats scheduling a PDSCH transmission to an NRUE can address RBs over all DL cell BW that includes the LTE DL cell BWand the NR DL cell BW. A CSI-RS transmission for NR UEs can be over allDL cell BW while a CSI-RS transmission for LTE UEs is only over the LTEDL cell BW. Different DMRS or CSI-RS structures can be used fortransmission on the LTE DL cell BW and on the NR DL cell BW. Forexample, the DMRS or CSI-RS structure on the LTE DL cell BW can be sameas for LTE UEs while the DMRS or CSI-RS structure on the NR DL cell BWcan be based on a CAZAC sequence or a different PN sequence.

FIG. 14 illustrates an example hybrid operation 1400 for an NR UE usingan LTE DL cell BW and an NR DL cell BW according to embodiments of thepresent disclosure. An embodiment of the hybrid operation 1400 shown inFIG. 14 is for illustration only. Other embodiments may be used withoutdeparting from the scope of the present disclosure.

An NR UE establishes an RRC connection with an eNB as an LTE UE. The NRUE is informed of an LTE DL cell BW 1410 through an LTE MIB and of anLTE UL cell BW through an LTE SIB2. The NR UE declares the NR UE'scapability for NR operation to the eNB. The NR UE is subsequentlyconfigured for operation on additional DL cell BW referred to as NR DLcell BW 1420, 1425. For example, the NR DL cell BW can include two BWswith equal size that are located on each side of the LTE DL cell BW. Itis also possible for the NR DL cell BW to instead include two BWs withunequal size that are located on each side of the LTE DL cell BW or asingle BW that is located on one side of the LTE DL cell BW or be a BWof a different carrier. The NR DL cell BW does not include transmissionof CRS, PBCH, SI, a physical control format indicator channel (PCFICH),or a physical H-ARQ indicator channel (PHICH). A PDCCH transmission foran NR UE can be located on the LTE DL cell BW 1430 or on the NR DL cellBW (both parts, when configured) 1440, 1445. An NR UE can be scheduledPDSCH reception on any set of RBs of the DL cell BW and the set of RBscan include RBs in the LTE DL cell BW and RBs in the NR DL cell BW.

As an LTE UE can be independently configured an LTE DL cell BW and anLTE UL cell BW, the LTE UL cell BW can include all UL cell BW and aconfiguration of a separate NR UL cell BW to NR UEs is not required. Forexample, a PUCCH region for LTE UEs can be placed on the two ends of theUL cell BW and the middle of the UL cell BW can be used for PUSCH,physical random access channel (PRACH), or SRS transmissions from LTEUEs or NR UEs.

When an NR UL cell BW is defined (similar to an NR DL cell BW), an NR UEcan operate: without PUCCH resources configured by higher layersignaling (can be shared, when needed, with LTE PUCCH resources);without PRACH resources configured by higher layer signaling (can beshared with LTE PRACH resources); and with SRS transmissions that arenot contiguous in BW to avoid an LTE UL cell BW.

An NR UE can dynamically switch operation between an LTE mode and an NRmode. This can be beneficial in several cases such as for enablingmulti-user MIMO with LTE-only capable UEs, or for enabling dynamicswitching of transmission from or transmission to an eNB that can servea macro-cell or a gNB that can serve a pico-cell, or for enabling robustfallback operation as a reception reliability using a CRS-based PDSCHtransmission mode can be higher than a reception reliability using aDMRS-based PDSCH transmission mode. To enable dynamic switching ofoperation for NR UEs between an LTE RAT and an NR RAT, in a firstexample an NR UE can be configured to monitor both an LTE-based DCIformat and an NR-based DCI format. In a second example, to avoidpotentially increasing a number of PDCCH decoding operations an NR UEneeds to perform per NR slot, the NR UE can be configured to decode asingle DCI format that can include an “operation mode” or “RAT mode”field (IE) of 1 bit that indicates an LTE-based transmission mode or anNR-based transmission mode for an associated PDSCH or PUSCH. Theremaining fields of the DCI format can be interpreted according to theindicated transmission mode where an interpretation of some fields, suchas a RB allocation field or a HARQ process number field or a TPC commandfield, can remain same in both transmission modes while aninterpretation of other fields that are applicable only for LTEoperation or only for NR operation can change. A slot structure, such asfor example a DMRS location and structure including a presence orabsence of DMRS, can also change depending on the operation mode.

FIG. 15 illustrates an example process 1500 for an NR UE to determinewhether to receive a PDSCH using a first transmission structure based onan LTE RAT or using a second transmission structure based on an NR RATaccording to embodiments of the present disclosure. An embodiment of theprocess 1500 shown in FIG. 15 is for illustration only. Otherembodiments may be used without departing from the scope of the presentdisclosure.

A UE establishes an RRC connection with an eNB and declares a capabilityto operate according to an NR RAT at step 1510. The UE is thenconfigured by the eNB to decode a first DCI format associated withreception of a PDSCH transmission or with a PUSCH transmission accordingto a first RAT, such as LTE, and a second DCI format associated withreception of a PDSCH transmission or with a PUSCH transmission accordingto a second RAT, such as NR. The UE decodes a first DCI format or asecond DCI format at step 1520. The first DCI format and the second DCIformat can have a different size or can have a same size and bedifferentiated by a “RAT mode” field. The UE determines whether the UEdetected the first DCI format or the second DCI format at step 1530.When the UE detects the first DCI format, the UE receives a PDSCH (ortransmits a PUSCH) according to a first RAT such as LTE at step 1540.When the UE detects the second DCI format, the UE receives a PDSCH (ortransmits a PUSCH) according to a second RAT such as NR at step 1550.

The present disclosure additionally relates to supporting a transmissionfor a first service type during a first time slot without interferingwith a transmission for a second service type during a second time slotthat includes the first time slot. The present disclosure also relatesto supporting a transmission for a first service type during a firsttime slot without interfering with another transmission for the firstservice type during the first time slot. The present disclosureadditionally relates to a gNB reducing a probability of collisionbetween a non-configured transmission and a configured transmission andto reduce a probability of collision between two non-configuredtransmissions. The present disclosure further relates to a gNBmultiplexing, over a common set of frequency resources and during a sametime, control transmissions to UEs supporting a first service type usinga first symbol duration for data transmission and to UEs supporting asecond service using a second symbol duration for data transmissions.The present disclosure also relates to a UE to informing a gNB of a UEidentity and of parameters for a transmission that is not configured bythe gNB.

An embodiment considers spectrum access means for UEs supporting a firstservice type, such as URLLC service, and for UEs supporting a secondservice type, such as eMBB service. A UE supporting the first servicetype transmits over a time slot having a first duration and a UEsupporting the second service type transmits over a time slot having asecond duration where the second duration is larger than the firstduration. For example, the first slot duration can be 0.1 msec while thesecond slot duration can be 0.5 msec.

When a second UE supporting the second service type has an ongoingsecond transmission during a slot with the second duration and a firstUE supporting the first service type needs to start a first transmissionduring a slot of a first duration that is within the slot of the secondduration, a collision of the two transmissions occurs when respectiveBWs at least partially overlap. To avoid such a collision, the first UEcan apply a listen-before-talk (LBT) type mechanism over an operating BWand select a transmission BW based on the LBT result. When the first UEneeds to transmit over a BW of T RBs in an operating BW of N RBs, thefirst UE can select the T RBs as the ones having a measured receivedpower that is the smaller than in the remaining N-T RBs. In this sense,a clear channel assessment (CCA) is different than a typical CCA in thata UE does not determine whether or not a received power is below athreshold over a system BW but instead determines a part of the systemBW, or of a configured portion of the system BW, where a received powerhas a low value. Certain RBs, such as RB that can be used for PUCCHtransmissions, can be excluded. Additionally, there can be restrictionsin the first RB used for a transmission or in the number of RBs used fora transmission as it is further subsequently described in order tofacilitate detection of the transmission at a gNB. For example, thefirst RB can be restricted to be a first RB every five RBs as the RBsare enumerated over an operating BW or over regions of an operating BWthat may be configured for UE transmissions that are not configured bythe gNB (autonomous UE transmissions).

In order to avoid collisions in accessing the channel medium with otherUEs having the first service type, the first UE can transmit areservation signal at least over the BW that the first UE determines fora subsequent transmission. The duration for the transmission of thereservation signal can be from the time the first UE determines the BWfor the subsequent transmission until the beginning of a transmissionslot for the first service type. Then, other UEs sensing the channelmedium to determine a BW with low interference for subsequenttransmissions will avoid the BW determined by the first UE for the UE'stransmission as the other UEs will sense a high interference in that BW.

When a non-configured transmission from a UE for a first service typeover a first time slot interferes with ongoing transmissions from otherUEs for a second service type over a second time slot, a gNB canmitigate an impact from the interference from the first service type byestimating and subtracting the interference from a received signal overthe first time slot. As the gNB typically receives the non-configuredtransmission for the first service type with a large power associatedwith a high detection reliability, the gNB can perform interferencecancellation of the non-configured transmission for the first servicetype from the ongoing transmissions for the second service type bydetecting, regenerating, and subtracting a signal corresponding to thefirst service type from the received signal.

FIG. 16 illustrates an example process 1600 for a UE supporting a firstservice type to determine a transmission BW according to embodiments ofthe present disclosure. An embodiment of the process 1600 shown in FIG.16 is for illustration only. Other embodiments may be used withoutdeparting from the scope of the present disclosure.

A UE supporting a first service type, such as URLLC service, determinesa time slot 1610 and prior to the time slot performs an LBT 1620 todetermine a power density profile 1630 for other transmissions over aBW. The BW can be the entire operating system BW or a BW that a servinggNB configures to the UE by higher layer signaling or by physical layersignaling. In the latter case, it is possible for a network to alsoapply frequency domain inter-cell interference coordination (ICIC) andprovide a level of protection for the configured BW from inter-cellinterference. Based on the measurement of the power profile, the UEselects a BW 1640 to transmit during the time slot.

A determination of a transmission power by a UE can be enhanced in orderto account for potential presence of interference. The UE can beconfigured by a serving gNB with an interference power reference value,P_(int,0), for the UE to incorporate in the determination of thetransmission power. As an outcome of the LBT, or at a somewhat earliertime instance, the UE measures an interference power, P_(int,meas), overa transmission BW. When P_(int,meas)≦P_(int,0), the UE determines aPUSCH transmission power as in Equation 1 while whenP_(int,meas)>P_(int,0), the UE increases a transmission power byP_(int,meas)−P_(int,0). Therefore, to account for the presence ofinterference, particularly from UEs supporting the second service typethat has lower transmission priority than the first service type, the UEcan add the term min(0,P_(int,meas)−P_(int,0)) in a formula, for examplesuch as the one in Equation 1, and the UE can determine a transmissionpower as in Equation 2 given by:

$\begin{matrix}{{P_{{PUSCH},c}(i)} = {\min {{\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{{10\; {\log_{10}\left( {M_{{PUSCH},c}(i)} \right)}} + {P_{{O\_ PUSCH},c}(j)} +} \\{{{\alpha_{c}(j)} \cdot {PL}_{c}} + {\Delta_{{TF},c}(i)} + {f_{c}(i)} +} \\{\min \left( {0,{P_{{int},{meas}} - P_{{int},0}}} \right)}\end{matrix}\end{Bmatrix}\lbrack{dBm}\rbrack}.}}} & {{Equation}\mspace{14mu} (2)}\end{matrix}$

A gNB can separately/independently configure values of P_(O) _(_)_(PUSCH,c)(j) and α_(c)(j) depending on a service type. For example, thegNB can configure a larger value for P_(O) _(_) _(PUSCH,c)(j) for URLLCservice relative to eMBB service when the former requires higherreliability. For example, the gNB can configure α_(c)(j)=1 for URLLCservice and α_(c)(j)<1 for eMBB service.

FIG. 17 illustrates an example process 1700 for a UE to determine atransmission power according to embodiments of the present disclosure.An embodiment of the process 1700 shown in FIG. 17 is for illustrationonly. Other embodiments may be used without departing from the scope ofthe present disclosure.

A gNB configures a UE with an interference power reference value at step1710. Prior to a transmission, the UE measures an interference powerover a transmission BW at step 1720. The UE determines whether or notP_(int,meas)≦P_(int,0) at step 1730. When P_(int,meas)≦P_(int,0), the UEtransmits with a transmission power that does not adjust for themeasured interference power (referred to, for brevity, as “nominal”power) at step 1740. When P_(int,meas)>P_(int,0), the UE increases thenominal transmission power by P_(int,meas)−P_(int,0) at step 1750.

Although a determination for a transmission power described in FIG. 17does not adjust a nominal transmission power whenP_(int,meas)≦P_(int,0), such adjustment (reduction) of the nominaltransmission can also be included at least when the nominal transmissionpower is larger than a configured value or a value determined by the UEor at least for some service or information types such as eMBB serviceor data (not control) information. Then, the nominal transmission poweris adjusted by P_(int,meas)−P_(int,0). Further when a UE is configuredto transmit data for the first service type and data for the secondservice type during a same time and the UE is power limited (requiredpower exceeds P_(CMAX,c)), the UE can prioritize power allocation to thetransmission of the first service type and reduce a power fortransmission of the second service type.

To reduce a probability of collisions among transmissions from UEssupporting the first service type over a same BW and a same time slot, aUE can determine a number of candidate transmission BWs andpseudo-randomly select one, for example based on the UE identity orbased on a randomly generated number. The transmission BW size and thenumber of candidate transmission BWs can be configured to the UE by aserving gNB. The UE can consider as candidate transmission BWs only theones resulting to a transmission power that is smaller than or equal toP_(CMAX,c) for the corresponding time slot.

A gNB can also perform a LBT to determine whether a UE with the firstservice type transmits in a BW over a time slot of a first duration. ThegNB can determine such transmission based on an increase in a receivedpower in the BW over the time slot as, for example, due to thesubstantially smaller duration of the first time slot relative to theduration of the second time slot, a transmission power over the BW fromthe UE with the first service type is typically larger than atransmission power over the BW from a UE with the second service type.The gNB can use this determination for the transmission from the UE withthe first service type to avoid processing receptions of transmissionsfrom UEs with the second service type over the BW during the first timeslot and to detect the information in the transmission from the UE withthe first service type. When the gNB fails to detect the informationfrom UEs with the second service type, due to the interference oftransmissions from UEs with the first service type, the gNB can schedulerespective retransmissions either for the respective data TBs or onlyfor interfered data CBs.

An interfered UE with second service type can also perform LBT todetermine whether or not a UE with first service type is transmitting inat least a partially overlapping BW. This requires transmission gapsduring a time slot with the second duration, for example at thebeginning of each time slot with the first duration that is includedwithin a time slot with a second duration when it is used fortransmission from the UE with the second service type, in order for theUE with the second service type to measure an interference power over aBW where the UE with the second service type transmits. When aninterference power over first parts of the BW exceeds a predeterminedthreshold, the UE with the second service type can suspend transmissionover at least the first parts of the BW in order to avoid creatinginterference to UEs with the first service type that are assumed to havehigher priority than the second service type.

In some embodiments, a gNB assistance to a UE for determining atransmission BW is considered during a time slot for a UE transmissionthat is not configured by the gNB. In one example, a gNB indicates byhigher layer signaling to a UE a set of one or more BW regions that theUE can use for transmissions to the gNB without associated UL grants. Inanother example, a gNB indicates by physical layer signaling a set ofone or more BW regions that a UE can use for transmissions that are notconfigured by the gNB. The physical layer signaling is through aUE-common control channel that is transmitted once per number of timeslots that is configured by system information or by UE-specific higherlayer signaling. The gNB can configure the UE with an RNTI forscrambling CRC bits appended to the DCI bits conveyed by the UE-commoncontrol channel. The UE-common control channel can convey DCI both forUEs supporting a first service type with transmissions over a time slothaving a first duration and for UEs supporting a second service typewith transmissions over a time slot having a second duration where thefirst slot duration is smaller than the second slot duration. Forexample, the first service type can be URLLC and the second service typecan be eMBB.

In yet another example, the mechanisms in the first example and in thesecond example can be combined. A gNB can configure a UE, by RRCsignaling, a BW for transmissions without associated UL grants and astarting RB for the BW within a total BW. The total BW can be an ULsystem BW or can be dynamically indicated by a UE-common controlchannel. For example, a gNB can configure a UE with a BW of 4 RBs fortransmissions without associated UL grants and with a second locationfor the 4 RBs within a total BW. The gNB can subsequently signal a totalBW of 40 RBs that is available for transmissions from UEs withoutassociated UL grants in a slot. Then, when a UE has data to transmit ina slot, the UE transmits an associated data channel (without anassociated UL grant) using the second 4 RBs within the total BW of 40RBs that is signaled by the UE-common control channel.

In one embodiment, the UE-common control channel (and other DL controlsignaling) is transmitted over one or more symbols that can either havea first duration or a second duration where the first symbol duration issmaller than the second symbol duration. The symbols can have the firstduration when the gNB supports both service types and can have thesecond duration when the gNB supports only the second service type. In asecond approach, the UE-common control channel is transmitted over oneor more symbols that have the first duration. The first approach or thesecond approach enable multiplexing, over a set of common time/frequencyresources, of DL control signaling for UEs supporting the first servicetype and for UEs supporting the second service type. Otherwise, when theDL control signaling is transmitted over symbols with the first durationfor UEs supporting the first service type and over symbols with thesecond duration for UEs supporting the second service type, frequencydivision multiplexing (FDM) is used for orthogonal multiplexing.

When a gNB transmits DL control channels, including a UE-common controlchannel, over multiple symbols of a slot, the gNB can transmit a RSassociated with the DL control channels. The association of the RS is atleast in terms of providing a channel estimate for UEs receiving the DLcontrol channels to obtain respective channel estimates for demodulationof respective DL control channels. The RS can be shared by multiple UEs,for example in a same manner as a RS for distributed EPDCCH transmissionor as a CRS for PDCCH transmission. When a DL control channel, includingthe UE-common control channel, is transmitted only over a single symbolof a slot, two approaches for a location of a RS that UEs can use fordemodulation of DL control channels are considered. In a first approach,the RS is located only in a first symbol from multiple symbols in theslot that a gNB uses to transmit DL control channels. The first approachrequires that second sub-bands of a DL system BW used to transmit DLcontrol channels in a symbol after a first symbol of a slot are asub-set of first sub-bands of the DL system BW used to transmit DLcontrol channels in symbols in the first symbol of the slot. In thismanner, an RS availability can be ensured for UEs receiving DL controlchannels in a symbol after the first symbol of the slot and the gNB doesnot transmit another RS in the symbol. In a second approach, fortransmission of a DL control channel in a symbol of a slot after a firstsymbol of the slot, there is no restriction on respective sub-bands anda gNB transmits an associated RS both in the first symbol and in thesymbol after the first symbol of the slot.

FIG. 18 illustrates an example dependence of symbol duration 1800 forcontrol signaling on supported service types according to embodiments ofthe present disclosure. An embodiment of the dependence of symbolduration 1800 shown in FIG. 18 is for illustration only. Otherembodiments may be used without departing from the scope of the presentdisclosure.

A gNB can configure a UE supporting a second service type, such as eMBBservice, for operation with a time slot structure that includes symbolswith substantially same duration for both control transmissions 1810 andfor data transmissions 1820 when the gNB does not communicate with UEssupporting a first service type, such as URLLC service. When the gNBcommunicates with UEs supporting the first service type and with UEssupporting the second service type, the gNB configures a UE supportingthe second service type for operation with a time slot structure thatincludes symbols with substantially different duration for controltransmissions 1830 than for data transmissions 1840 where the symbolduration for control transmissions is smaller than the symbol durationfor data transmission. Not all symbols with the smaller duration need tobe used for control transmissions; for example, subsequent symbols withthe smaller duration can be used for transmission of data associatedwith the first service type. The symbol duration for controltransmissions is substantially same as the symbol duration used fortransmissions of data for the first service type. The same can apply fora symbol duration conveying a DMRS so that DMRS multiplexing betweennon-configured and configured transmissions can be orthogonal and anon-configured transmission will not cause an inability for a gNB toobtain a channel estimate for a configured transmission. For example,for both UEs supporting a first service type and UEs supporting a secondservice type, a DMRS symbol can have a duration determined as for thefirst service type and can be placed in a first or in a second symbol asit is subsequently further described.

When a UE supporting the first service type detects the UE-commoncontrol channel, the UE prioritizes a selection of a transmission BWwithin the indicated total transmission BW for transmission during atime slot. When the UE does not detect the UE-common control channel,the UE can select a BW for transmission during a time slot based onother criteria such as, for example, based on an LBT over a totaloperating system BW to determine a transmission BW with sufficiently lowinterference power spectral density as described in the firstembodiment, or based on a BW indicated in a last UE-common controlchannel that the UE detected. The UE can also perform an LBT within anindicated total BW when the UE detects the UE-common control channel.

A gNB can implement several approaches for indicating a total BW to a UEfor non-configured transmissions within the total BW during a time slot.In a first approach, the gNB can configure a partition of an operatingsystem BW into a number of regions and indicate one or more of theregions. For example, the gNB can partition an operating system BW of100 RBs in four non-overlapping regions of successive or interleaved 25RBs, and the gNB can use a bit-map of 4 bits to indicate one or more ofthe four regions, for example by using a binary value of “1” to indicatethat a region is included in the total BW. For example, this approachcan be combined with dynamic frequency-domain ICIC. In a secondapproach, the gNB can configure a region and indicate RBs within theregion. For example, this approach can be combined with semi-staticfrequency domain ICIC. For example, for an operating BW of 100 RBs, thegNB can configure to the UE a region that includes the first 24 RBs. ThegNB can indicate through a UE-common control channel, transmitted in thebeginning of a time slot having a second duration, RBs within the regionof first 24 RBs that form the total BW. For example, indication can beby indicating one or more of two groups where each group includes 12RBs, the two groups do not include common RBs, and the 12 RBs can be 12consecutive RBs starting from the first RB from the 24 RBs or can beinterleaved and include every second RB starting from the first or thesecond RB for the first or second group, respectively.

FIG. 19 illustrates an example process 1900 for a gNB to communicate atthe beginning of a second time slot a total BW available for potentialtransmissions from UEs during a first time slot according to embodimentsof the present disclosure. An embodiment of the process 1900 shown inFIG. 19 is for illustration only. Other embodiments may be used withoutdeparting from the scope of the present disclosure.

A gNB transmits a UE-common control channel in a first symbol 1910 of atime slot having a second duration 1920 and on fixed or pseudo-randomlydetermined resources within a predetermined BW. For example, the timeslot with the second duration can be for transmissions associated witheMBB service. The UE-common control channel includes informationindicating a set of RBs of an operating BW for transmissions over a timeslot having a first duration 1930 that is smaller than the secondduration. For example, the time slot with the first duration can be fortransmissions associated with URLLC service. For example, the indicationcan be for a set of RBs in one or more of a first 1940, second 1942,third 1944, and fourth 1946, regions of an operating BW. Upon receivingthe indication for the set of RBs, either through the UE-common controlchannel or through higher layer signaling, a UE having a transmissionover a time slot with the first duration, selects RBs from the indicatedset of RBs.

In some embodiments, a configuration by a gNB of a CP length for a UE isconsidered to use for transmission of symbols depending on a servicetype or depending on whether or not the UE and the gNB synchronized UEtransmissions.

A first service type can occasionally require extremely low latency thatcannot be fulfilled when an associated UE performs a random accessprocedure with a gNB prior to transmission of data associated with thefirst service type. As prior to transmission the UE can synchronize withthe gNB based on signals transmitted from the gNB, such assynchronization signals or RS, the UE and the gNB have a differenttiming that corresponds at least to the trip delay for signals from thegNB to the UE. Further, signals transmitted from the UE to the gNB alsoincur a trip delay and the arrival timing, relative to the local timingat the gNB, is practically different by an amount corresponding to theround trip delay. For relatively large cell sizes, such as in the orderof 1 Km or larger, the unsynchronized transmissions from the UE cancreate inter-symbol interference and also interfere with othertransmissions. Such a problem does not exist for transmissions from thegNB that originate from a same transmitter and can therefore besynchronized.

When a cell size is large enough for a round trip delay fortransmissions from a UE can approach or exceed a CP length used fortransmission from the gNB to UEs (referred to as nominal CP length).When the UE does not perform a random access procedure prior totransmission to the gNB so that the UE can have a valid timing advance(TA) command from the gNB, the gNB can configure the UE with a different(larger) CP length for transmissions from the UE to the gNB than fortransmissions from the gNB to the UE. The CP length configuration can beUE-specific or service type specific. For example, a gNB can configureUEs with URLLC service that do not perform a random access procedure anddo not have a valid TA command, to transmit symbols with a larger CPlength than for symbols transmitted from the gNB to UEs or for symbolstransmitted from UEs with eMBB service that perform a random accessprocedure prior to data transmissions.

It is possible that a UE with URLLC service also has another type oflatency non-sensitive service, such as an eMBB service, and the UEperformed a random access process before first transmitting data for thenon-latency sensitive service and data for the URLLC service arrivinglater for transmission. In such case, even though the UE did not performa random access process before transmitting data for the URLLC service,the UE has a valid TA command and can use a shorter CP for transmittingsymbols conveying URLLC data information. Therefore, a UE needs to applya longer CP, when configured by a gNB, only when the UE does not have avalid TA command such as when the UE exits a discontinuous reception(DRX) state and transmits after synchronizing with the gNB but prior toperforming a random access procedure. The gNB and the UE can have a sameunderstanding of whether or not the UE has a valid TA command, forexample when different frequency resource are configured fortransmissions with a nominal CP and for transmissions with a configuredCP, or the gNB can attempt to detect a transmission from the UEaccording to both hypotheses for a CP length, or a UE can use aconfigured CP length for a first service type, such as URLLC service,and use a nominal CP, such as a same CP as for receptions from the gNB,for a second service type such as an eMBB service.

A configuration for a different CP length for symbols transmitted from agNB and doe symbols transmitted by a UE can also apply for cases wheregNB transmission points are different than gNB reception points and apropagation delay can be respectively different.

FIG. 20 illustrates an example process 2000 for a UE to determine a CPto use for transmissions according to embodiments of the presentdisclosure. An embodiment of the process 2000 shown in FIG. 20 is forillustration only. Other embodiments may be used without departing fromthe scope of the present disclosure.

A gNB configures a UE with a CP to apply for transmissions with a validTA at step 2010. When the UE needs to transmit data, the UE determinesan associated service type in order to determine a transmission formatsuch as time slot duration and CP length for transmission symbols atstep 2020. When the service is not of a first type requiring lowlatency, the UE transmits associated information by applying a nominalCP to transmission symbols at step 2030. When the service is of a firsttype requiring low latency, the UE transmits associated information byapplying a configured CP to transmission symbols at step 2040.

In some embodiments, mechanisms for a UE to facilitate a gNB areconsidered to detect a transmission from the UE that is not configuredby the gNB. A transmission by a UE that is not configured by a gNB caninclude control information about associated data transmissionparameters. A first RB for the transmission of the control informationcan be restricted in order to facilitate detection at a gNB. Forexample, the first RB can be every fifth RB or every tenth RB of anoperating BW or of one or more configured BW regions. In case a UE canselect from multiple starting RBs for a non-configured transmission, theselection can be pseudo-random for example based on a UE identity. Forthe transmission of control information, the UE can either use apredetermined number of RBs or use a variable number of RBs, from apredetermined set of numbers of RBs. When the UE uses a predeterminednumber of RBs, the UE can adjust a transmission power in order toachieve a target reception reliability for the control information. Whenthe UE uses a variable number of RBs, the UE can adjust both atransmission power and a number of RBs to achieve target receptionreliability for the control information. The gNB can then performmultiple decoding operations according to each possible number of RBs inthe predetermined set of numbers of RBs, in order to detect the controlinformation. This is subsequently described in detail.

A first time slot symbol for the transmission of the control informationcan be either the first symbol or the second symbol, after includingDMRS in the first symbol, of the time slot. The control information caninclude a field indicating an MCS used for the data transmission, afield indicating a RB allocation for the data transmission, and anidentity for the UE in order for the gNB to identify the UE associatedwith a transmission that was not configured by the gNB. The UE canencode the control information, for example using a tail bitingconvolutional code (TBCC) or a polar code. Unlike DCI formattransmissions by the gNB, an associated CRC for the control informationtransmitted by the UE is not scrambled by a RNTI, such as a RNTI derivedby the UE identity, as otherwise it would not be practically possiblefor the gNB to confirm correct detection for the control information.

FIG. 21 illustrates an example arrangement 2100 of RS, control symbols,and data symbols in a time slot used by a UE to transmit anon-configured transmission according to embodiments of the presentdisclosure. An embodiment of the example arrangement 2100 shown in FIG.21 is for illustration only. Other embodiments may be used withoutdeparting from the scope of the present disclosure.

As shown in FIG. 21, in a time slot 2110 that includes, for example,seven symbols, a UE transmits a DMRS for demodulation of controlinformation and of data information in a first symbol of the time slot2110 in order to enable a serving gNB to obtain a channel estimate anddemodulate without additional delay the control information that the UEtransmits in a second symbol 2120 and the data information that the UEtransmits in the remaining symbols of the time slot 2130, 2132, 2134,2136, and 2138. The DMRS can also serve to enable the gNB todetect/identify a subsequent non-configured transmission. The DMRS canbe based on a CAZAC sequence, such as a Zadoff-Chu sequence, or can bebased on a random access preamble that can also enable synchronizationand serve as DMRS. The frequency resources for the transmission caninclude a number of RBs, from a predetermined number of RBs, such as 5,10, 20 and so on RBs, and the starting RB can be, for example everyfifth RB 2140, 2142, 2144, 2146, in an operating BW or in one or moreconfigured BW regions while any remaining RB, such as RB 2150, can beused for the DMRS/control/data transmissions but cannot be a starting RBfor the mapping of the transmissions onto the frequency resources. It isalso possible that transmission can only start at a predetermined RBsuch as the first RB and this can further simplify a blind detection fora non-configured transmission by the gNB.

When a target reception reliability can be provided when both DMRS andcontrol information and DMRS are multiplexed in the first symbol of thetime slot, the UE can transmit DMRS on some of the SCs, for example onevery other SC, and transmit control information in the remaining SCs inthe first symbol of the time slot. For example, such multiplexing canapply when the payload of the control information is small or when theUE experiences a sufficiently high SINR. For example, the multiplexingstructure of control information and DMRS can be configured by a gNB.When control information is transmitted only in the first symbol of thetime slot, data information can be transmitted in all remaining symbols.A corresponding illustration is omitted for brevity.

When a retransmission of a data TB from a UE is scheduled by a gNB, theUE does not need to transmit control information. When incrementalredundancy is used for a retransmission, SCs used for transmission ofcontrol information can be used for transmission of data information.When chase combining is used for a retransmission, SCs used fortransmission of control information can be used either for DMRStransmission, or for shifting the data transmission by one symbol andterminating the transmission one symbol earlier, or can be used toprovide additional, separately encoded information, such as a bufferstatus report, a power headroom report, or an (RSRP report, or can beleft empty.

A non-configured PUSCH transmission from a UE to a serving gNB typicallyconveys a small data TB and, in case of a high reception reliabilityrequirement for the data TB, the data TB is encoded with a low coderate. For such operating scenarios, there is little benefit from usingincremental redundancy (IR) for retransmissions, chase combining (CC)can apply, and the control information associated with a transmission ofa data TB does not need to include a redundancy version (RV) field.Further, retransmissions of a data TB can be configured by the gNB,non-configured transmission from a UE can be limited only to initialtransmission for a data TB, and then the control information also doesnot need to include a new data indicator (NDI) field. Additionally,non-configured PUSCH transmissions are typically intended to convey asingle data TB, retransmissions can be scheduled as fast as in animmediately next time slot, and therefore do not require multiple HARQprocesses and the control information does not need to include a HARQprocess field. The DMRS associated with the PUSCH transmission can havea predetermined configuration, such as a predetermined cyclic shiftconfigured in advance by UE-specific higher layer signaling or, in orderto increase a probability for orthogonal DMRS multiplexing in case ofcollisions among non-configured transmissions from multiple UEs inoverlapping frequency resource during a time slot, the UE canpseudo-randomly select a cyclic shift for the DMRS, for exampleaccording to the UE identity. For example, for a total of N_(CS) cyclicshifts, a UE can select a cyclic shift index as UE_ID mod N_(CS) whereUE_ID is the UE identity that is configured in advance to the UE by thegNB through higher layer signaling. In case of two UE transmitterantennas, the CS for the DMRS transmission from the second antenna canbe determined as (UE_ID mod N_(CS)+└N_(CS)/2┘)mod N_(CS). In case offour UE transmitter antennas, the CS for the DMRS from the second,third, and fourth antennas can be determined as (UE_ID modN_(CS)+└N_(CS)/2┘)mod N_(CS), (UE_ID mod N_(CS)+└N_(CS)/4┘)mod N_(CS),and (UE_ID mod N_(CS)+└3·N_(CS)/4┘)mod N_(CS) where └ ┘ is the floorfunction that decreases a number to the previous integer.

Based on the above, a control information transmitted from a UE andproviding information for a non-configured transmission from the UE caninclude one or more of a UE identity, an MCS, and a RB allocation. Thecontrol information can be transmitted using QPSK modulation. The datainformation can also be transmitted using QPSK modulation and thissubstantially limits the number of possible MCS considering a typicallysmall target code rate; nevertheless, it is not required that datatransmission uses only QPSK modulation and higher modulation orders,such as QAM16, can also apply. For example, when a UE determines a RSRPlarger than a first threshold (or a path-loss smaller than a secondthreshold), the UE uses QAM16 modulation; otherwise the UE uses QPSKmodulation. For example, when the UE generates data information bitsabove a threshold, the UE uses QAM16 modulation; otherwise, the UE usesQPSK modulation. For example, the modulation scheme can be configured inadvance to the UE by the gNB. Moreover, the RB allocation can bedetermined based only on a first RB and a number of allocated RBs. TheRB distribution can be predetermined, starting from the RB index of thefirst RB for the control information transmission and continuing for anumber of consecutive RB indexes or for a number of interleaved RBindexes such as every second RB index. The control information canadditionally include a buffer-status report that the gNB can use toschedule subsequent transmissions in order to improve receptionrobustness for data information relative to non-configuredtransmissions.

Target code rates, or equivalently target spectral efficiency values,for control information and for data information (with CRC) in order toachieve respective reception reliability targets can depend on a networkdeployment and on a serving gNB implementation and can be configured toa UE by the gNB for a service type. When the UE needs to perform anon-configured transmission to the gNB, the UE can determine a number ofcontrol information bits (if not predetermined) and a number of datainformation bits and CRC bits. Based on a RSRP measurement and on thereference transmission power of the signal used for the RSRPmeasurement, the UE can determine a path-loss. Using the configuredspectral efficiency values and the path-loss, the UE can determine atransmission power, for example as in Equation 1 or Equation 2. Unless anumber of RBs used by the UE for the non-configured transmission ispredetermined or preconfigured by the gNB, the UE can adjust the numberof RBs in order to achieve the target spectral efficiency or,equivalently, a target code rate. For example, assuming that the controlinformation transmitted from a UE to a serving gNB includes a UEidentity field of 16 bits, a data MCS field of 2 bits, and a data RBallocation field of 2 bits, the total control information is 20 bitsand, for a RB that includes 12 sub-carriers, a target code rate of 1/12can be achieved by transmitting the control information over20*12/(2*12)=10 RBs in one symbol of a time slot while a target coderate of 1/6 can be achieved by transmitting the control information over20*12/(2*6)=5 RBs in one symbol of a time slot.

The control information and the data information do not need to betransmitted over a same number of RBs as a different number of RBs canbe required to achieve a respective target code rate. The same appliesfor respective transmission powers. Nevertheless, to simplify overalloperation, simplify UE transmitter and gNB receiver implementations, anduse a same DMRS to demodulate both control information and datainformation, the RBs and the power can be same for the transmission ofcontrol information and data information. Then, a RB allocation fielddoes not need to be included in the control information transmitted fromthe UE. For example, a UE can determine the RBs to be the larger of thenumber of RBs required for the control information or for the datainformation to achieve a respective target code rate.

FIG. 22 illustrates an example process 2200 for a UE to determine anumber of RBs and a transmission power for a non-configured transmissionaccording to embodiments of the present disclosure. An embodiment of theprocess 2200 shown in FIG. 22 is for illustration only. Otherembodiments may be used without departing from the scope of the presentdisclosure.

A UE receives configuration information from a gNB for at least for atarget code rate for transmitting data information and CRC bits at step2210. The UE determines a number of data information bits and CRC bitsfor non-configured transmission in a time slot at step 2220.Subsequently, based on the target code rate and the number datainformation and CRC bits, the UE determine a number of RBs for thenon-configured transmission at step 2230. For example, denoting byr_(max) the target code rate, by O_(data)+O_(CRC) the number of datainformation bit and CRC bits, for N_(sc) ^(RB) the number of sub-carrierper RB, and for QPSK modulation, the number of RBs N_(RB) can bedetermined as N_(RB)=┌(O_(data)+O_(CRC))/(2·N_(sc) ^(RB)·r_(max))┐. TheUE also measures a RSRP and derives a path-loss at step 2240. The RSRPmeasurement can occur before, or after, or at a same time as thedetermination for the non-configured transmission. Based on thedetermination for a number of RBs and for a path-loss, the UE determinesa transmission power at step 2250, for example as in Equation 1 orEquation 2. Finally, the UE, at step 2260, transmits DMRS, controlinformation and data information and CRC using the determinedtransmission power in the RBs during the time slot.

When a gNB detects the control information but fails to detect the dataTB, the gNB can schedule a retransmission of the data TB by transmittinga DCI format in a PDCCH. The PDCCH conveying the DCI format schedulingthe data TB retransmission can be transmitted after a predeterminednumber of time slots of first duration that the gNB can inform to UEs byUE-common higher layer signaling, such as broadcast system information,or by UE-specific higher layer signaling, or the number of time slotscan be specified in the system operation. The gNB scrambles a CRC of theDCI format with the identity of the UE that the eNB determines from thecontrol information transmitted from the UE. The DCI format canadditionally include one or more of an MCS, a RB allocation, and a DMRSCS field. The DCI format can additionally include a TPC command for theretransmission. The DCI format can additionally include a TA command forthe retransmission. Then, a non-configured transmission for an initialtransmission of a data TB can use a first CP length and a configuredretransmission for the data TB can use a second CP length where thesecond CP length is smaller than the first CP length. In case the DCIformat transmitted from the gNB addresses multiple UEs, it can act as aDCI scheduling an RAR where a CRC is scrambled by a UE-common RNTI andthe RAR fields include the identity for one or more UEs and at least oneof an MCS, RB allocation, DMRS CS, TPC, or TA field.

Similar to the PDCCH transmission, the UE transmits a PUSCH conveying aretransmission of the data TB after a predetermined number of time slotsof first duration that the gNB can inform to UEs by UE-common higherlayer signaling, such as broadcast system information, or by UE-specifichigher layer signaling, or the number of time slots can be specified inthe system operation.

A HARQ-ACK transmission from a UE in response to a scheduled datatransmission of a first service type, such as URLLC service, from a gNBto the UE can also be scheduled in order to avoid or reduce interferenceto the HARQ-ACK transmission from UEs with ongoing transmissionsassociated to a second type service, such as eMBB service. Therefore, aDCI format scheduling data transmission of a first service type to a UEcan include a field indicating frequency resources for correspondingHARQ-ACK transmission from the UE. For example, the frequency resourcescan include a starting RB in a system BW. When the total number of RBsfor HARQ-ACK transmission is not configured in advance by the gNB orspecified in the system operation, the DCI format can also include thenumber of RBs. When a timing of HARQ-ACK transmission from a UE relativeto a time slot of a corresponding data transmission to the UE is not isnot configured in advance by the gNB or specified in the systemoperation, the DCI format can also include the HARQ-ACK transmissiontiming.

When a UE does not detect in a time slot a DCI format scheduling aretransmission of a data TB, the UE repeats the initial transmission ofthe data TB in the first available time slot.

Although the present disclosure has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

None of the description in this application should be read as implyingthat any particular element, step, or function is an essential elementthat must be included in the claims scope. The scope of patented subjectmatter is defined only by the claims. Moreover, none of the claims areintended to invoke 35 U.S.C. § 112(f) unless the exact words “means for”are followed by a participle.

What is claimed is:
 1. A user equipment (UE) operating with a new radio(NR) radio access technology (RAT), the UE comprising: a transceiverconfigured to: receive synchronization signals and a master informationblock (MIB) in a first bandwidth (BW); and receive a physical downlinkcontrol channel (PDCCH) in a second BW wherein the second BW isindicated by an offset in the MIB relative to the first BW and the PDCCHconveys a downlink control information (DCI) format that configures areception of a first system information block (SIB).
 2. The UE of claim1, wherein the first SIB indicates a number of antenna ports used fortransmission of a common reference signal (CRS) according to a long termevolution (LTE) RAT.
 3. The UE of claim 2, wherein the transceiver isfurther configured to transmit a signal according to the NR RAT with apower determined according to a path-loss measured from the CRS.
 4. TheUE of claim 1, wherein the transceiver is further configured to receivean indication to perform a first number of decoding operations for PDCCHreceptions conveying a first DCI format according to the NR RAT and asecond number of decoding operations for PDCCH receptions conveying asecond DCI format according to a long term evolution (LTE) RAT.
 5. TheUE of claim 4, wherein the transceiver is further configured to receivean indication to perform a third number of decoding operations for PDCCHreceptions according to the NR RAT when the UE does not also performdecoding operations for PDCCH receptions according to the LTE RAT. 6.The UE of claim 1, wherein the transceiver is further configured toreceive an indication in the MIB for an absence or presence of a longterm evolution (LTE) RAT.
 7. The UE of claim 1, wherein the transceiveris further configured to: receive a subframe number and a downlink BWfor a long term evolution (LTE) RAT; determine symbols and subcarriersused for transmissions of synchronization signals and of MIB accordingto the LTE RAT; and perform a rate matching operation for NR RATreceptions around the symbols and subcarriers.
 8. The UE of claim 1,wherein the SIB indicates: configuration information for transmission ofchannel state information reference signals (CSI-RS) according to a longterm evolution (LTE) RAT; configuration information for a partitioningof a predetermined number of subframes in a normal subframes and inmulticast-broadcast single-frequency network (MBSFN) subframes accordingto the LTE RAT; and a configuration for a first number of subframesymbols in each normal subframe and for a second number of subframesymbols in each MBSFN subframe, and wherein the transceiver is furtherconfigured to exclude from NR RAT receptions symbols and subcarriers ofthe transmission of the CSI-RS, the first number of subframe symbols,and the second number of subframe symbols.
 9. A first base stationoperating with a new-radio (NR) radio access technology (RAT), the firstbase station comprising: a transceiver configured to transmit, to asecond base station that uses a long term evolution (LTE) RAT, a firstsignal over a first link, wherein the first signal indicates a bandwidthfor transmission of synchronization signals and a first systeminformation block according to the NR RAT.
 10. The first base station ofclaim 9, wherein the transceiver is further configured to receive asecond signal, from the second base station over a second link, thesecond signal indicating a number of decoding operations for a physicaldownlink control channel (PDCCH) to configure a user equipment (UE). 11.The first base station of claim 9, wherein the transceiver is furtherconfigured to receive a second signal, from the second base station,over a second link, wherein the second signal comprises: configurationinformation for partitioning a predetermined number of subframes innormal subframes and in multicast-broadcast single-frequency network(MBSFN) subframes according to the LTE RAT; and configurationinformation for a first number of subframe symbols in each normalsubframe and for a second number of subframe symbols in each MBSFNsubframe, and wherein the first base station does not transmit in thefirst number of subframe symbols or in the second number of subframesymbols.
 12. The first base station of claim 9, wherein the transceiveris further configured to receive a second signal, from the second basestation, over a second link, the second signal indicating a cellidentity and a number of antenna ports for transmitting a commonreference signal (CRS) from the second base station, and wherein symbolsand subcarriers of CRS transmission are determined from the number ofantenna ports.
 13. The first base station of claim 9, wherein thetransceiver is further configured to receive a second signal, from thesecond base station, over a second link, the second signal comprisingconfiguration information for receiving sounding reference signals (SRS)from the second base station, and wherein symbols of SRS receptions aredetermined from the configuration information.
 14. The first basestation of claim 9, wherein the transceiver is further configured toreceive a second signal, from the second base station, over a secondlink, the second signal comprising configuration information fordownlink, uplink, and special subframes over a frame of ten subframesaccording to the LTE RAT.
 15. A method of a user equipment (UE)operating with a new radio (NR) radio access technology (RAT), themethod comprising: receiving synchronization signals and a masterinformation block (MIB) in a first bandwidth (BW); and receiving aphysical downlink control channel (PDCCH) in a second BW wherein thesecond BW is indicated by an offset in the MIB relative to the first BWand the PDCCH conveys a downlink control information (DCI) format thatconfigures a reception of a first system information block (SIB). 16.The method of claim 15, wherein the first SIB indicates a number ofantenna ports used for transmission of a common reference signal (CRS)according to a long term evolution (LTE) RAT.
 17. The method of claim16, further comprising transmitting a signal according to the NR RATwith a power determined according to a path-loss measured from areception of the CRS.
 18. The method of claim 15, further comprisingreceiving an indication to perform a first number of decoding operationsfor PDCCH receptions conveying a first DCI format according to the NRRAT and a second number of decoding operations for PDCCH receptionsconveying a second DCI format according to a long term evolution (LTE)RAT.
 19. The method of claim 18, further comprising receiving anindication to perform a third number of decoding operations for PDCCHreceptions according to the NR RAT when the UE does not perform decodingoperations for PDCCH receptions according to the LTE RAT.
 20. The methodof claim 15, further comprising receiving an indication in the MIB foran absence or presence of a long term evolution (LTE) RAT.